diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-chart/analytics-chart-utils.ts b/apps/frontend/src/components/analytics-dashboard/analytics-chart/analytics-chart-utils.ts
index 84144f344e..5c42fbd129 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-chart/analytics-chart-utils.ts
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-chart/analytics-chart-utils.ts
@@ -1,6 +1,7 @@
 import type { Labrinth } from '@modrinth/api-client'
 
 import {
+	type AnalyticsBreakdownGroup,
 	type AnalyticsBreakdownPreset,
 	type AnalyticsDashboardProject,
 	type AnalyticsDashboardStat,
@@ -17,6 +18,7 @@ import {
 	analyticsStatCardMessages,
 	formatAnalyticsDependentProjectFallbackLabel,
 	formatAnalyticsDownloadReasonLabel,
+	formatAnalyticsDownloadSourceLabel,
 	formatAnalyticsLoaderLabel,
 	formatAnalyticsMonetizationLabel,
 } from '../analytics-messages'
@@ -30,6 +32,10 @@ import {
 	isUnknownAnalyticsBreakdownValue,
 	UNKNOWN_BREAKDOWN_VALUE,
 } from '../breakdown'
+import {
+	applyAnalyticsBreakdownGroup,
+	getAnalyticsBreakdownGroupSeriesName,
+} from '../breakdown-groups'
 import { PREVIOUS_PERIOD_DATASET_ID_PREFIX } from './analytics-chart-constants'
 
 export type ChartDataset = {
@@ -168,6 +174,9 @@ export function formatBreakdownLabel(
 	if (selectedBreakdown === 'download_reason') {
 		return formatAnalyticsDownloadReasonLabel(normalizedLowercaseValue, formatMessage)
 	}
+	if (selectedBreakdown === 'user_agent') {
+		return formatAnalyticsDownloadSourceLabel(normalizedValue, formatMessage)
+	}
 	if (selectedBreakdown === 'dependent_project_download') {
 		if (isNoDependentAnalyticsBreakdownValue(breakdownValue)) {
 			return formatMessage(analyticsMessages.noDependent)
@@ -412,6 +421,7 @@ export function buildChartDatasets(
 	getVersionProjectName: ((versionId: string) => string | undefined) | undefined,
 	formatMessage: FormatMessage,
 	sliceCount: number = timeSlices.length,
+	breakdownGroup?: AnalyticsBreakdownGroup | null,
 ): ChartDataset[] {
 	const selectedProjectIds = new Set(selectedProjects.map((project) => project.id))
 	if (selectedProjectIds.size === 0) {
@@ -428,6 +438,14 @@ export function buildChartDatasets(
 		return collapseRepeatedUnknownBreakdownLabels(
 			normalizedBreakdowns.map((breakdown, index) => {
 				const breakdownValue = breakdownValues[index] ?? ''
+				if (breakdown === breakdownGroup?.breakdown) {
+					const seriesName = getAnalyticsBreakdownGroupSeriesName(
+						breakdownValue,
+						breakdownGroup,
+						formatMessage(analyticsMessages.other),
+					)
+					if (seriesName) return seriesName
+				}
 				if (breakdown === 'project' || breakdown === 'dependent_project_download') {
 					if (
 						breakdown === 'dependent_project_download' &&
@@ -464,7 +482,7 @@ export function buildChartDatasets(
 
 	if (
 		normalizedBreakdowns.length > 0 &&
-		!(normalizedBreakdowns.length === 1 && normalizedBreakdowns[0] === 'project')
+		!(normalizedBreakdowns.length === 1 && normalizedBreakdowns[0] === 'project' && !breakdownGroup)
 	) {
 		const hasVersionBreakdown = normalizedBreakdowns.includes('version_id')
 		const hasDependentProjectBreakdown = normalizedBreakdowns.includes('dependent_project_download')
@@ -488,10 +506,10 @@ export function buildChartDatasets(
 					continue
 				}
 
-				const breakdownValues = getAnalyticsBreakdownValues(
-					point,
+				const breakdownValues = applyAnalyticsBreakdownGroup(
+					getAnalyticsBreakdownValues(point, normalizedBreakdowns, formatMessage),
 					normalizedBreakdowns,
-					formatMessage,
+					breakdownGroup,
 				)
 				if (breakdownValues.some((breakdownValue) => breakdownValue === ALL_BREAKDOWN_VALUE)) {
 					continue
@@ -543,11 +561,14 @@ export function buildChartDatasets(
 				'dependent_project_download',
 			)
 			const versionName =
-				hasVersionBreakdown && versionBreakdownIndex !== -1
+				hasVersionBreakdown &&
+				versionBreakdownIndex !== -1 &&
+				breakdownGroup?.breakdown !== 'version_id'
 					? getVersionDisplayName?.(breakdownValues[versionBreakdownIndex] ?? '')
 					: undefined
 			const dependentProjectId =
-				dependentProjectBreakdownIndex !== -1
+				dependentProjectBreakdownIndex !== -1 &&
+				breakdownGroup?.breakdown !== 'dependent_project_download'
 					? breakdownValues[dependentProjectBreakdownIndex]
 					: undefined
 			const dependentProjectName = dependentProjectId
@@ -556,7 +577,9 @@ export function buildChartDatasets(
 					: (projectNamesById.get(dependentProjectId) ?? dependentProjectId)
 				: undefined
 			const versionProjectName =
-				normalizedBreakdowns.length === 1 && normalizedBreakdowns[0] === 'version_id'
+				normalizedBreakdowns.length === 1 &&
+				normalizedBreakdowns[0] === 'version_id' &&
+				breakdownGroup?.breakdown !== 'version_id'
 					? getVersionProjectName?.(breakdownValues[0] ?? '')
 					: undefined
 			const dependencyProjectNames = [...(dependentOnProjectIdsByBreakdown.get(breakdownKey) ?? [])]
@@ -575,7 +598,7 @@ export function buildChartDatasets(
 							)
 				: undefined
 			const color =
-				normalizedBreakdowns.length === 1
+				normalizedBreakdowns.length === 1 && !breakdownGroup
 					? getBreakdownColor(
 							breakdownValues[0] ?? '',
 							normalizedBreakdowns[0],
diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-chart/use-analytics-chart-datasets.ts b/apps/frontend/src/components/analytics-dashboard/analytics-chart/use-analytics-chart-datasets.ts
index 482c879002..9cd15c9c9c 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-chart/use-analytics-chart-datasets.ts
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-chart/use-analytics-chart-datasets.ts
@@ -5,6 +5,7 @@ import { computed, type ComputedRef, ref, watch } from 'vue'
 import { useTheme } from '~/composables/nuxt-accessors'
 import { isDarkTheme } from '~/plugins/theme/index.ts'
 import type {
+	AnalyticsBreakdownGroup,
 	AnalyticsBreakdownPreset,
 	AnalyticsDashboardContextValue,
 	AnalyticsDashboardProject,
@@ -51,6 +52,7 @@ export function useAnalyticsChartDatasets(
 		| 'displayedSelectedGroupBy'
 		| 'displayedSelectedBreakdowns'
 		| 'displayedSelectedFilters'
+		| 'resolvedActiveBreakdownGroup'
 		| 'hiddenGraphDatasetIds'
 		| 'hasExplicitGraphDatasetSelection'
 		| 'isGraphDatasetSelectionActive'
@@ -175,6 +177,7 @@ export function useAnalyticsChartDatasets(
 			showProjectVersionNames.value ? context.getVersionProjectName : undefined,
 			formatMessage,
 			sliceCount.value,
+			context.resolvedActiveBreakdownGroup.value,
 		),
 	)
 	const previousChartDatasetsByStat = computed<Record<AnalyticsDashboardStat, ChartDataset[]>>(() =>
@@ -191,6 +194,7 @@ export function useAnalyticsChartDatasets(
 			showProjectVersionNames.value ? context.getVersionProjectName : undefined,
 			formatMessage,
 			sliceCount.value,
+			context.resolvedActiveBreakdownGroup.value,
 		),
 	)
 	const allChartDatasets = computed(() => chartDatasetsByStat.value[context.activeStat.value])
@@ -384,6 +388,7 @@ function buildDatasetsByStat(
 	getVersionProjectName: ((versionId: string) => string | undefined) | undefined,
 	formatMessage: FormatMessage,
 	sliceCount: number,
+	breakdownGroup: AnalyticsBreakdownGroup | null,
 ) {
 	const datasetsByStat = {} as Record<AnalyticsDashboardStat, ChartDataset[]>
 	for (const stat of ANALYTICS_DASHBOARD_STATS) {
@@ -401,6 +406,7 @@ function buildDatasetsByStat(
 			getVersionProjectName,
 			formatMessage,
 			sliceCount,
+			breakdownGroup,
 		)
 	}
 	return datasetsByStat
diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-messages.ts b/apps/frontend/src/components/analytics-dashboard/analytics-messages.ts
index 49a0b7ea27..d3bf81b33a 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-messages.ts
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-messages.ts
@@ -32,6 +32,14 @@ export const analyticsMessages = defineMessages({
 		id: 'analytics.action.refresh',
 		defaultMessage: 'Refresh',
 	},
+	saveButton: {
+		id: 'analytics.action.save',
+		defaultMessage: 'Save',
+	},
+	cancelButton: {
+		id: 'analytics.action.cancel',
+		defaultMessage: 'Cancel',
+	},
 	fetchingResults: {
 		id: 'analytics.loading.fetching-results',
 		defaultMessage: 'Fetching results...',
@@ -129,6 +137,102 @@ export const analyticsMessages = defineMessages({
 		id: 'analytics.query.label.breakdown',
 		defaultMessage: 'Breakdown:',
 	},
+	breakdownGroupsButton: {
+		id: 'analytics.breakdown-groups.button',
+		defaultMessage: 'Group series',
+	},
+	breakdownGroupsNoGrouping: {
+		id: 'analytics.breakdown-groups.none',
+		defaultMessage: 'No grouping',
+	},
+	breakdownGroupsCreate: {
+		id: 'analytics.breakdown-groups.create',
+		defaultMessage: 'Create group',
+	},
+	breakdownGroupsEdit: {
+		id: 'analytics.breakdown-groups.edit',
+		defaultMessage: 'Edit group',
+	},
+	breakdownGroupsDelete: {
+		id: 'analytics.breakdown-groups.delete',
+		defaultMessage: 'Delete group',
+	},
+	breakdownGroupsDeleteTitle: {
+		id: 'analytics.breakdown-groups.delete-title',
+		defaultMessage: 'Delete {name}?',
+	},
+	breakdownGroupsDeleteDescription: {
+		id: 'analytics.breakdown-groups.delete-description',
+		defaultMessage: 'This saved breakdown group will be permanently deleted from this browser.',
+	},
+	breakdownGroupsModalCreateTitle: {
+		id: 'analytics.breakdown-groups.modal.create-title',
+		defaultMessage: 'Create breakdown group',
+	},
+	breakdownGroupsModalEditTitle: {
+		id: 'analytics.breakdown-groups.modal.edit-title',
+		defaultMessage: 'Edit breakdown group',
+	},
+	breakdownGroupsGroupName: {
+		id: 'analytics.breakdown-groups.group-name',
+		defaultMessage: 'Group name',
+	},
+	breakdownGroupsGroupNamePlaceholder: {
+		id: 'analytics.breakdown-groups.group-name-placeholder',
+		defaultMessage: 'For example, Platform families',
+	},
+	breakdownGroupsSeriesName: {
+		id: 'analytics.breakdown-groups.series-name',
+		defaultMessage: 'Series name',
+	},
+	breakdownGroupsSeriesValues: {
+		id: 'analytics.breakdown-groups.series-values',
+		defaultMessage: 'Breakdown values',
+	},
+	breakdownGroupsSelectValues: {
+		id: 'analytics.breakdown-groups.select-values',
+		defaultMessage: 'Select values',
+	},
+	breakdownGroupsAddSeries: {
+		id: 'analytics.breakdown-groups.add-series',
+		defaultMessage: 'Add series',
+	},
+	breakdownGroupsRemoveSeries: {
+		id: 'analytics.breakdown-groups.remove-series',
+		defaultMessage: 'Remove series',
+	},
+	breakdownGroupsOtherDescription: {
+		id: 'analytics.breakdown-groups.other-description',
+		defaultMessage: '{count, plural, one {# unassigned value} other {# unassigned values}}',
+	},
+	breakdownGroupsUnavailableValue: {
+		id: 'analytics.breakdown-groups.unavailable-value',
+		defaultMessage: '{value} (not in current results)',
+	},
+	breakdownGroupsNameRequired: {
+		id: 'analytics.breakdown-groups.validation.name-required',
+		defaultMessage: 'Enter a group name.',
+	},
+	breakdownGroupsNameDuplicate: {
+		id: 'analytics.breakdown-groups.validation.name-duplicate',
+		defaultMessage: 'A group with this name already exists for this breakdown.',
+	},
+	breakdownGroupsSeriesRequired: {
+		id: 'analytics.breakdown-groups.validation.series-required',
+		defaultMessage: 'Add at least one custom series.',
+	},
+	breakdownGroupsSeriesNameRequired: {
+		id: 'analytics.breakdown-groups.validation.series-name-required',
+		defaultMessage: 'Every custom series needs a name.',
+	},
+	breakdownGroupsSeriesNameDuplicate: {
+		id: 'analytics.breakdown-groups.validation.series-name-duplicate',
+		defaultMessage: 'Custom series names must be unique.',
+	},
+	breakdownGroupsSeriesValuesRequired: {
+		id: 'analytics.breakdown-groups.validation.series-values-required',
+		defaultMessage: 'Assign at least one breakdown value to every custom series.',
+	},
 	addFilterButton: {
 		id: 'analytics.query.filter.add',
 		defaultMessage: 'Add filter',
diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-columns.ts b/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-columns.ts
index 21cae3cd79..f69574febe 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-columns.ts
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-columns.ts
@@ -1,6 +1,7 @@
 import type { TableColumn } from '@modrinth/ui'
 
 import type {
+	AnalyticsBreakdownGroup,
 	AnalyticsBreakdownPreset,
 	AnalyticsDashboardStat,
 	AnalyticsSelectedFilters,
@@ -23,6 +24,7 @@ type BuildAnalyticsTableColumnsOptions = {
 	selectedBreakdowns: readonly AnalyticsTableBreakdownPreset[]
 	selectedFilters: AnalyticsSelectedFilters
 	showBreakdownColumn: boolean
+	breakdownGroup: AnalyticsBreakdownGroup | null
 	formatMessage: FormatMessage
 	getRelevantAnalyticsDashboardStats: (
 		breakdowns: readonly AnalyticsBreakdownPreset[],
@@ -42,6 +44,7 @@ export function buildAnalyticsTableColumns({
 	selectedBreakdowns,
 	selectedFilters,
 	showBreakdownColumn,
+	breakdownGroup,
 	formatMessage,
 	getRelevantAnalyticsDashboardStats,
 }: BuildAnalyticsTableColumnsOptions): TableColumn<AnalyticsTableColumnKey>[] {
@@ -62,7 +65,10 @@ export function buildAnalyticsTableColumns({
 		for (const breakdown of selectedBreakdowns) {
 			nextColumns.push({
 				key: getAnalyticsTableBreakdownColumnKey(breakdown),
-				label: getAnalyticsTableBreakdownColumnLabel(breakdown, formatMessage),
+				label:
+					breakdownGroup?.breakdown === breakdown
+						? breakdownGroup.name
+						: getAnalyticsTableBreakdownColumnLabel(breakdown, formatMessage),
 				enableSorting: true,
 				width: breakdown === 'project' && selectedBreakdowns.length === 1 ? '45%' : undefined,
 			})
diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-row-builder.ts b/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-row-builder.ts
index a4fe46007c..3cebe494e2 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-row-builder.ts
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-table/analytics-table-row-builder.ts
@@ -1,6 +1,7 @@
 import type { Labrinth } from '@modrinth/api-client'
 
 import {
+	type AnalyticsBreakdownGroup,
 	type AnalyticsBreakdownPreset,
 	type AnalyticsDashboardStat,
 	type AnalyticsSelectedFilters,
@@ -28,6 +29,10 @@ import {
 	isNoDependentAnalyticsBreakdownValue,
 	isUnknownAnalyticsBreakdownValue,
 } from '../breakdown'
+import {
+	applyAnalyticsBreakdownGroup,
+	getAnalyticsBreakdownGroupSeriesName,
+} from '../breakdown-groups'
 import { getAnalyticsTableBreakdownColumnKey } from './analytics-table-columns'
 import type {
 	AnalyticsTableBreakdownDisplayValues,
@@ -43,6 +48,7 @@ type BuildAnalyticsTableRowsOptions = {
 	fetchRequest: Labrinth.Analytics.v3.FetchRequest | null
 	timeSlices: Labrinth.Analytics.v3.TimeSlice[]
 	selectedBreakdowns: readonly AnalyticsTableBreakdownPreset[]
+	breakdownGroup: AnalyticsBreakdownGroup | null
 	selectedProjectIds: ReadonlySet<string>
 	selectedFilters: AnalyticsSelectedFilters
 	dependentProjectTypesById: ReadonlyMap<string, readonly string[]>
@@ -62,6 +68,7 @@ export function buildAnalyticsTableRows({
 	fetchRequest,
 	timeSlices,
 	selectedBreakdowns,
+	breakdownGroup,
 	selectedProjectIds,
 	selectedFilters,
 	dependentProjectTypesById,
@@ -94,6 +101,14 @@ export function buildAnalyticsTableRows({
 		breakdownValue: string,
 		breakdown: AnalyticsTableBreakdownPreset,
 	) {
+		if (breakdown === breakdownGroup?.breakdown) {
+			const seriesName = getAnalyticsBreakdownGroupSeriesName(
+				breakdownValue,
+				breakdownGroup,
+				formatMessage(analyticsMessages.other),
+			)
+			if (seriesName) return seriesName
+		}
 		const key = `${breakdown}:${breakdownValue}`
 		let displayValue = breakdownDisplayValues.get(key)
 		if (displayValue === undefined) {
@@ -112,7 +127,11 @@ export function buildAnalyticsTableRows({
 
 	function getProjectDisplayValueForBreakdownValues(breakdownValues: readonly string[]) {
 		const versionBreakdownIndex = selectedBreakdowns.indexOf('version_id')
-		if (versionBreakdownIndex === -1 || selectedBreakdowns.includes('project')) {
+		if (
+			versionBreakdownIndex === -1 ||
+			selectedBreakdowns.includes('project') ||
+			breakdownGroup?.breakdown === 'version_id'
+		) {
 			return ''
 		}
 
@@ -131,7 +150,7 @@ export function buildAnalyticsTableRows({
 
 	function getProjectVersionIdForBreakdownValues(breakdownValues: readonly string[]) {
 		const versionBreakdownIndex = selectedBreakdowns.indexOf('version_id')
-		if (versionBreakdownIndex === -1) {
+		if (versionBreakdownIndex === -1 || breakdownGroup?.breakdown === 'version_id') {
 			return ''
 		}
 
@@ -253,7 +272,12 @@ export function buildAnalyticsTableRows({
 		createRow(ALL_PROJECTS_BREAKDOWN_VALUE, [])
 	}
 
-	if (!includeDate && selectedBreakdowns.length === 1 && selectedBreakdowns[0] === 'project') {
+	if (
+		!includeDate &&
+		selectedBreakdowns.length === 1 &&
+		selectedBreakdowns[0] === 'project' &&
+		breakdownGroup?.breakdown !== 'project'
+	) {
 		for (const projectId of selectedProjectIds) {
 			createRow(projectId, [projectId])
 		}
@@ -285,10 +309,15 @@ export function buildAnalyticsTableRows({
 				continue
 			}
 
-			const breakdownValues =
+			const rawBreakdownValues =
 				selectedBreakdowns.length === 0
 					? []
 					: getAnalyticsBreakdownValues(point, selectedBreakdowns, formatMessage)
+			const breakdownValues = applyAnalyticsBreakdownGroup(
+				rawBreakdownValues,
+				selectedBreakdowns,
+				breakdownGroup,
+			)
 			if (breakdownValues.some((breakdownValue) => breakdownValue === ALL_BREAKDOWN_VALUE)) {
 				continue
 			}
diff --git a/apps/frontend/src/components/analytics-dashboard/analytics-table/index.vue b/apps/frontend/src/components/analytics-dashboard/analytics-table/index.vue
index 2b625b3a9b..b4873c70b9 100644
--- a/apps/frontend/src/components/analytics-dashboard/analytics-table/index.vue
+++ b/apps/frontend/src/components/analytics-dashboard/analytics-table/index.vue
@@ -56,7 +56,9 @@
 				<span class="text-primary">{{ value }}</span>
 			</template>
 			<template #cell-breakdown_project="{ row, value }">
+				<span v-if="isGroupedBreakdown('project')" class="mr-2.5 text-primary">{{ value }}</span>
 				<ProjectCell
+					v-else
 					:label="getProjectCellLabel(value)"
 					:icon-url="getProjectIconUrl(row.breakdownValues.project)"
 					:icon-tooltip="getProjectCellLabel(value)"
@@ -78,8 +80,10 @@
 				<span class="mr-2.5 text-primary">{{ value }}</span>
 			</template>
 			<template #cell-breakdown_user_id="{ row, value }">
+				<span v-if="isGroupedBreakdown('user_id')" class="mr-2.5 text-primary">{{ value }}</span>
 				<component
 					:is="getUserPageHref(row.breakdownValues.user_id) ? 'a' : 'span'"
+					v-else
 					:href="getUserPageHref(row.breakdownValues.user_id)"
 					:target="getUserPageHref(row.breakdownValues.user_id) ? '_blank' : undefined"
 					:rel="getUserPageHref(row.breakdownValues.user_id) ? 'noopener noreferrer' : undefined"
@@ -104,7 +108,11 @@
 				</component>
 			</template>
 			<template #cell-breakdown_dependent_project_download="{ row, value }">
+				<span v-if="isGroupedBreakdown('dependent_project_download')" class="mr-2.5 text-primary">
+					{{ value }}
+				</span>
 				<ProjectCell
+					v-else
 					:label="getProjectCellLabel(value)"
 					:icon-url="
 						isMissingDependentProjectValue(row.breakdownValues.dependent_project_download)
@@ -124,8 +132,10 @@
 				/>
 			</template>
 			<template #cell-breakdown_version_id="{ row, value }">
+				<span v-if="isGroupedBreakdown('version_id')" class="mr-2.5 text-primary">{{ value }}</span>
 				<component
 					:is="getVersionPageHref(row.projectVersionId) ? 'a' : 'span'"
+					v-else
 					v-tooltip="getVersionProjectName(row.projectVersionId)"
 					:href="getVersionPageHref(row.projectVersionId)"
 					:target="getVersionPageHref(row.projectVersionId) ? '_blank' : undefined"
@@ -276,6 +286,7 @@ const {
 	displayedSelectedGroupBy: selectedGroupBy,
 	displayedSelectedBreakdowns: selectedBreakdowns,
 	displayedSelectedFilters: selectedFilters,
+	resolvedActiveBreakdownGroup,
 	displayedFetchRequest: fetchRequest,
 	displayedTimeSlices: timeSlices,
 	activeStat,
@@ -407,9 +418,11 @@ const emptyTableMessage = computed(() => {
 })
 
 const breakdownColumnLabel = computed(() =>
-	selectedBreakdowns.value.length === 1
-		? getAnalyticsTableBreakdownColumnLabel(selectedBreakdowns.value[0], formatMessage)
-		: formatMessage(analyticsBreakdownMessages.breakdown),
+	resolvedActiveBreakdownGroup.value
+		? resolvedActiveBreakdownGroup.value.name
+		: selectedBreakdowns.value.length === 1
+			? getAnalyticsTableBreakdownColumnLabel(selectedBreakdowns.value[0], formatMessage)
+			: formatMessage(analyticsBreakdownMessages.breakdown),
 )
 const relevantStats = computed(
 	() =>
@@ -430,6 +443,7 @@ function buildTableRows(mode: AnalyticsTableMode) {
 		fetchRequest: fetchRequest.value,
 		timeSlices: timeSlices.value,
 		selectedBreakdowns: selectedBreakdowns.value,
+		breakdownGroup: resolvedActiveBreakdownGroup.value,
 		selectedProjectIds: selectedProjectIdSet.value,
 		selectedFilters: selectedFilters.value,
 		dependentProjectTypesById: dependentProjectTypesById.value,
@@ -454,6 +468,7 @@ function buildColumns(includeDate: boolean) {
 		selectedBreakdowns: selectedBreakdowns.value,
 		selectedFilters: selectedFilters.value,
 		showBreakdownColumn: showBreakdownColumn.value,
+		breakdownGroup: resolvedActiveBreakdownGroup.value,
 		formatMessage,
 		getRelevantAnalyticsDashboardStats,
 	})
@@ -463,6 +478,10 @@ function getProjectIconUrl(projectId: string | undefined) {
 	return projectId ? projectIconUrlsById.value.get(projectId) : undefined
 }
 
+function isGroupedBreakdown(breakdown: string) {
+	return resolvedActiveBreakdownGroup.value?.breakdown === breakdown
+}
+
 function getProjectOrganizationName(projectId: string | undefined) {
 	return projectId ? projectOrganizationNamesById.value.get(projectId) : undefined
 }
@@ -592,6 +611,7 @@ watch(
 		selectedProjectIds,
 		selectedGroupBy,
 		selectedBreakdowns,
+		resolvedActiveBreakdownGroup,
 		selectedFilters,
 		projects,
 		dependentProjectTypesById,
diff --git a/apps/frontend/src/components/analytics-dashboard/breakdown-groups.ts b/apps/frontend/src/components/analytics-dashboard/breakdown-groups.ts
new file mode 100644
index 0000000000..775c61bb8d
--- /dev/null
+++ b/apps/frontend/src/components/analytics-dashboard/breakdown-groups.ts
@@ -0,0 +1,60 @@
+import type {
+	AnalyticsBreakdownGroup,
+	AnalyticsBreakdownPreset,
+} from '~/providers/analytics/analytics'
+
+export const ANALYTICS_BREAKDOWN_GROUP_OTHER_SERIES_ID = '__other__'
+const GROUPED_BREAKDOWN_VALUE_PREFIX = '__breakdown_group__:'
+
+export function createAnalyticsBreakdownGroupId(): string {
+	if (typeof crypto !== 'undefined' && typeof crypto.randomUUID === 'function') {
+		return crypto.randomUUID()
+	}
+	return `${Date.now().toString(36)}-${Math.random().toString(36).slice(2)}`
+}
+
+export function getAnalyticsBreakdownGroupValue(groupId: string, seriesId: string): string {
+	return `${GROUPED_BREAKDOWN_VALUE_PREFIX}${encodeURIComponent(groupId)}:${encodeURIComponent(seriesId)}`
+}
+
+export function getAnalyticsBreakdownGroupSeriesId(value: string): string | null {
+	if (!value.startsWith(GROUPED_BREAKDOWN_VALUE_PREFIX)) return null
+	const encodedParts = value.slice(GROUPED_BREAKDOWN_VALUE_PREFIX.length).split(':')
+	if (encodedParts.length !== 2) return null
+	try {
+		return decodeURIComponent(encodedParts[1] ?? '') || null
+	} catch {
+		return null
+	}
+}
+
+export function getAnalyticsBreakdownGroupSeriesName(
+	value: string,
+	group: AnalyticsBreakdownGroup | null | undefined,
+	otherLabel: string,
+): string | undefined {
+	if (!group) return undefined
+	const seriesId = getAnalyticsBreakdownGroupSeriesId(value)
+	if (!seriesId) return undefined
+	if (seriesId === ANALYTICS_BREAKDOWN_GROUP_OTHER_SERIES_ID) return otherLabel
+	return group.series.find((series) => series.id === seriesId)?.name
+}
+
+export function applyAnalyticsBreakdownGroup(
+	values: readonly string[],
+	breakdowns: readonly AnalyticsBreakdownPreset[],
+	group: AnalyticsBreakdownGroup | null | undefined,
+): string[] {
+	const nextValues = [...values]
+	if (!group) return nextValues
+	const breakdownIndex = breakdowns.findIndex((breakdown) => breakdown === group.breakdown)
+	if (breakdownIndex === -1) return nextValues
+	const rawValue = nextValues[breakdownIndex]
+	if (!rawValue) return nextValues
+	const series = group.series.find((candidate) => candidate.values.includes(rawValue))
+	nextValues[breakdownIndex] = getAnalyticsBreakdownGroupValue(
+		group.id,
+		series?.id ?? ANALYTICS_BREAKDOWN_GROUP_OTHER_SERIES_ID,
+	)
+	return nextValues
+}
diff --git a/apps/frontend/src/components/analytics-dashboard/breakdown.ts b/apps/frontend/src/components/analytics-dashboard/breakdown.ts
index b7388cf4ac..9b88c26416 100644
--- a/apps/frontend/src/components/analytics-dashboard/breakdown.ts
+++ b/apps/frontend/src/components/analytics-dashboard/breakdown.ts
@@ -13,7 +13,7 @@ export const COMBINED_BREAKDOWN_DATASET_ID_PREFIX = 'breakdowns:'
 export function getAnalyticsBreakdownValue(
 	point: Labrinth.Analytics.v3.ProjectAnalytics,
 	selectedBreakdown: AnalyticsBreakdownPreset,
-	formatMessage: FormatMessage,
+	_formatMessage: FormatMessage,
 ): string {
 	switch (selectedBreakdown) {
 		case 'none':
@@ -29,13 +29,10 @@ export function getAnalyticsBreakdownValue(
 			return ALL_BREAKDOWN_VALUE
 		}
 		case 'user_agent': {
-			const downloadSource = normalizeBreakdownValue(
+			return normalizeBreakdownValue(
 				'user_agent' in point ? point.user_agent : undefined,
 				UNKNOWN_BREAKDOWN_VALUE,
 			)
-			return downloadSource === UNKNOWN_BREAKDOWN_VALUE
-				? UNKNOWN_BREAKDOWN_VALUE
-				: getDownloadSourceLabel(downloadSource, formatMessage)
 		}
 		case 'download_reason':
 			return normalizeBreakdownValue(
diff --git a/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupModal.vue b/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupModal.vue
new file mode 100644
index 0000000000..c7d74e6ffe
--- /dev/null
+++ b/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupModal.vue
@@ -0,0 +1,342 @@
+<template>
+	<NewModal
+		ref="modal"
+		:header="modalTitle"
+		max-width="calc(100vw - 2rem)"
+		width="720px"
+		:on-hide="resetDraft"
+	>
+		<div class="flex flex-col gap-5">
+			<label class="flex flex-col gap-2 font-semibold text-primary">
+				{{ formatMessage(analyticsMessages.breakdownGroupsGroupName) }}
+				<StyledInput
+					v-model="draftName"
+					:placeholder="formatMessage(analyticsMessages.breakdownGroupsGroupNamePlaceholder)"
+				/>
+			</label>
+
+			<div class="flex flex-col gap-3">
+				<div
+					v-for="(series, seriesIndex) in draftSeries"
+					:key="series.id"
+					class="flex flex-col gap-3 rounded-xl border border-solid border-surface-5 bg-surface-2 p-4"
+				>
+					<div class="flex items-end gap-2">
+						<label class="flex min-w-0 flex-1 flex-col gap-2 font-semibold text-primary">
+							{{ formatMessage(analyticsMessages.breakdownGroupsSeriesName) }}
+							<StyledInput v-model="series.name" />
+						</label>
+						<ButtonStyled circular type="transparent">
+							<button
+								type="button"
+								:aria-label="formatMessage(analyticsMessages.breakdownGroupsRemoveSeries)"
+								@click="removeSeries(seriesIndex)"
+							>
+								<TrashIcon />
+							</button>
+						</ButtonStyled>
+					</div>
+					<label class="flex flex-col gap-2 font-semibold text-primary">
+						{{ formatMessage(analyticsMessages.breakdownGroupsSeriesValues) }}
+						<MultiSelect
+							v-model="series.values"
+							:options="getSeriesOptions(series.id)"
+							:placeholder="formatMessage(analyticsMessages.breakdownGroupsSelectValues)"
+							searchable
+							fuzzy-search
+							:clearable="false"
+							checkbox-position="right"
+							:max-tag-rows="2"
+						>
+							<template #input-content="{ isOpen, selectedOptions }">
+								<div class="flex min-h-8 min-w-0 flex-1 items-center gap-2">
+									<span
+										class="min-w-0 flex-1 truncate font-medium"
+										:class="selectedOptions.length === 0 ? 'text-secondary' : 'text-primary'"
+									>
+										{{
+											selectedOptions.length === 0
+												? formatMessage(analyticsMessages.breakdownGroupsSelectValues)
+												: selectedOptions.map((option) => option.label).join(', ')
+										}}
+									</span>
+									<ChevronLeftIcon
+										class="size-5 shrink-0 text-secondary transition-transform duration-150"
+										:class="isOpen ? 'rotate-90' : '-rotate-90'"
+									/>
+								</div>
+							</template>
+						</MultiSelect>
+					</label>
+				</div>
+
+				<ButtonStyled type="transparent" class="w-fit">
+					<button type="button" @click="addSeries">
+						<PlusIcon />
+						{{ formatMessage(analyticsMessages.breakdownGroupsAddSeries) }}
+					</button>
+				</ButtonStyled>
+			</div>
+
+			<div class="rounded-xl border border-solid border-surface-5 bg-surface-2 p-4">
+				<div class="font-semibold text-contrast">{{ formatMessage(analyticsMessages.other) }}</div>
+				<div class="mt-1 text-sm text-secondary">
+					{{
+						formatMessage(analyticsMessages.breakdownGroupsOtherDescription, {
+							count: unassignedValueCount,
+						})
+					}}
+				</div>
+			</div>
+
+			<p v-if="validationMessage" class="m-0 text-sm font-semibold text-red">
+				{{ validationMessage }}
+			</p>
+		</div>
+
+		<template #actions>
+			<div class="flex justify-end gap-2">
+				<ButtonStyled type="transparent">
+					<button type="button" @click="modal?.hide()">
+						{{ formatMessage(analyticsMessages.cancelButton) }}
+					</button>
+				</ButtonStyled>
+				<ButtonStyled color="brand">
+					<button type="button" :disabled="Boolean(validationMessage)" @click="save">
+						{{ formatMessage(analyticsMessages.saveButton) }}
+					</button>
+				</ButtonStyled>
+			</div>
+		</template>
+	</NewModal>
+</template>
+
+<script setup lang="ts">
+import type { Labrinth } from '@modrinth/api-client'
+import { ChevronLeftIcon, PlusIcon, TrashIcon } from '@modrinth/assets'
+import {
+	ButtonStyled,
+	MultiSelect,
+	type MultiSelectOption,
+	NewModal,
+	StyledInput,
+	useVIntl,
+} from '@modrinth/ui'
+
+import { createAnalyticsBreakdownGroupId } from '~/components/analytics-dashboard/breakdown-groups'
+import {
+	type AnalyticsBreakdownGroup,
+	type AnalyticsBreakdownGroupSeries,
+	type AnalyticsBreakdownPreset,
+	doesAnalyticsPointMatchNormalizedFilters,
+	getProjectIdsMatchingStatusFilter,
+	injectAnalyticsDashboardContext,
+	normalizeAnalyticsSelectedFilters,
+} from '~/providers/analytics/analytics'
+
+import { formatBreakdownLabel } from '../analytics-chart/analytics-chart-utils'
+import { analyticsMessages } from '../analytics-messages'
+import {
+	ALL_BREAKDOWN_VALUE,
+	getAnalyticsBreakdownValue,
+	isNoDependentAnalyticsBreakdownValue,
+	isUnknownAnalyticsBreakdownValue,
+} from '../breakdown'
+
+type Breakdown = Exclude<AnalyticsBreakdownPreset, 'none'>
+
+const emit = defineEmits<{
+	save: [group: AnalyticsBreakdownGroup, activate: boolean]
+}>()
+
+const {
+	breakdownGroups,
+	displayedTimeSlices,
+	displayedSelectedProjectIds,
+	displayedSelectedFilters,
+	projectStatusById,
+	dependentProjectTypesById,
+	projectNamesById,
+	userNamesById,
+	getVersionDisplayName,
+} = injectAnalyticsDashboardContext()
+const { formatMessage } = useVIntl()
+const modal = ref<InstanceType<typeof NewModal> | null>(null)
+const editingGroupId = ref<string | null>(null)
+const draftBreakdown = ref<Breakdown>('country')
+const draftName = ref('')
+const draftSeries = ref<AnalyticsBreakdownGroupSeries[]>([])
+
+const modalTitle = computed(() =>
+	formatMessage(
+		editingGroupId.value
+			? analyticsMessages.breakdownGroupsModalEditTitle
+			: analyticsMessages.breakdownGroupsModalCreateTitle,
+	),
+)
+
+const availableValueSet = computed(
+	() => new Set(availableValues.value.map((option) => option.value)),
+)
+const availableValues = computed<MultiSelectOption<string>[]>(() => {
+	const projectIds = new Set(
+		getProjectIdsMatchingStatusFilter(
+			displayedSelectedProjectIds.value,
+			projectStatusById.value,
+			displayedSelectedFilters.value,
+		),
+	)
+	const normalizedFilters = normalizeAnalyticsSelectedFilters(displayedSelectedFilters.value)
+	const values = new Set<string>()
+	for (const slice of displayedTimeSlices.value) {
+		for (const point of slice) {
+			if (!isProjectAnalyticsPoint(point) || !projectIds.has(point.source_project)) continue
+			if (
+				!doesAnalyticsPointMatchNormalizedFilters(
+					point,
+					normalizedFilters,
+					dependentProjectTypesById.value,
+				)
+			) {
+				continue
+			}
+			const value = getAnalyticsBreakdownValue(point, draftBreakdown.value, formatMessage)
+			if (value !== ALL_BREAKDOWN_VALUE) values.add(value)
+		}
+	}
+	return [...values]
+		.map((value) => ({ value, label: getValueLabel(value) }))
+		.sort((left, right) => left.label.localeCompare(right.label))
+})
+
+const allDraftValues = computed(() => draftSeries.value.flatMap((series) => series.values))
+const unassignedValueCount = computed(() => {
+	const assignedValues = new Set(allDraftValues.value)
+	return availableValues.value.filter((option) => !assignedValues.has(option.value)).length
+})
+
+const validationMessage = computed(() => {
+	const normalizedName = draftName.value.trim().toLocaleLowerCase()
+	if (!normalizedName) return formatMessage(analyticsMessages.breakdownGroupsNameRequired)
+	if (
+		breakdownGroups.value.some(
+			(group) =>
+				group.breakdown === draftBreakdown.value &&
+				group.id !== editingGroupId.value &&
+				group.name.trim().toLocaleLowerCase() === normalizedName,
+		)
+	) {
+		return formatMessage(analyticsMessages.breakdownGroupsNameDuplicate)
+	}
+	if (draftSeries.value.length === 0) {
+		return formatMessage(analyticsMessages.breakdownGroupsSeriesRequired)
+	}
+	const names = draftSeries.value.map((series) => series.name.trim().toLocaleLowerCase())
+	if (names.some((name) => !name)) {
+		return formatMessage(analyticsMessages.breakdownGroupsSeriesNameRequired)
+	}
+	if (new Set(names).size !== names.length) {
+		return formatMessage(analyticsMessages.breakdownGroupsSeriesNameDuplicate)
+	}
+	if (draftSeries.value.some((series) => series.values.length === 0)) {
+		return formatMessage(analyticsMessages.breakdownGroupsSeriesValuesRequired)
+	}
+	return ''
+})
+
+function isProjectAnalyticsPoint(
+	point: Labrinth.Analytics.v3.AnalyticsData,
+): point is Labrinth.Analytics.v3.ProjectAnalytics {
+	return 'source_project' in point
+}
+
+function getValueLabel(value: string) {
+	if (draftBreakdown.value === 'project' || draftBreakdown.value === 'dependent_project_download') {
+		if (isNoDependentAnalyticsBreakdownValue(value)) {
+			return formatMessage(analyticsMessages.noDependent)
+		}
+		if (!isUnknownAnalyticsBreakdownValue(value)) {
+			return projectNamesById.value.get(value) ?? value
+		}
+	}
+	return formatBreakdownLabel(
+		value,
+		draftBreakdown.value,
+		getVersionDisplayName,
+		userNamesById.value,
+		formatMessage,
+	)
+}
+
+function getSeriesOptions(seriesId: string): MultiSelectOption<string>[] {
+	const selectedByOtherSeries = new Set(
+		draftSeries.value.filter((series) => series.id !== seriesId).flatMap((series) => series.values),
+	)
+	const currentSeries = draftSeries.value.find((series) => series.id === seriesId)
+	const unavailableValues = (currentSeries?.values ?? []).filter(
+		(value) => !availableValueSet.value.has(value),
+	)
+	return [
+		...availableValues.value.map((option) => ({
+			...option,
+			disabled: selectedByOtherSeries.has(option.value),
+		})),
+		...unavailableValues.map((value) => ({
+			value,
+			label: formatMessage(analyticsMessages.breakdownGroupsUnavailableValue, {
+				value: getValueLabel(value),
+			}),
+		})),
+	]
+}
+
+function createEmptySeries(): AnalyticsBreakdownGroupSeries {
+	return { id: createAnalyticsBreakdownGroupId(), name: '', values: [] }
+}
+
+function addSeries() {
+	draftSeries.value.push(createEmptySeries())
+}
+
+function removeSeries(index: number) {
+	draftSeries.value.splice(index, 1)
+}
+
+function show(breakdown: Breakdown, group?: AnalyticsBreakdownGroup, event?: MouseEvent) {
+	draftBreakdown.value = breakdown
+	editingGroupId.value = group?.id ?? null
+	draftName.value = group?.name ?? ''
+	draftSeries.value = group
+		? group.series.map((series) => ({ ...series, values: [...series.values] }))
+		: [createEmptySeries()]
+	modal.value?.show(event)
+}
+
+function resetDraft() {
+	editingGroupId.value = null
+	draftName.value = ''
+	draftSeries.value = []
+}
+
+function save() {
+	if (validationMessage.value) return
+	const isNewGroup = editingGroupId.value === null
+	emit(
+		'save',
+		{
+			id: editingGroupId.value ?? createAnalyticsBreakdownGroupId(),
+			name: draftName.value.trim(),
+			breakdown: draftBreakdown.value,
+			series: draftSeries.value.map((series) => ({
+				id: series.id,
+				name: series.name.trim(),
+				values: [...new Set(series.values)],
+			})),
+		},
+		isNewGroup,
+	)
+	modal.value?.hide()
+}
+
+defineExpose({ show })
+</script>
diff --git a/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupOptionMenu.vue b/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupOptionMenu.vue
new file mode 100644
index 0000000000..fb1df2b9e7
--- /dev/null
+++ b/apps/frontend/src/components/analytics-dashboard/query-builder/BreakdownGroupOptionMenu.vue
@@ -0,0 +1,330 @@
+<template>
+	<ConfirmModal
+		ref="deleteModal"
+		:markdown="false"
+		:title="deleteTitle"
+		:description="formatMessage(analyticsMessages.breakdownGroupsDeleteDescription)"
+		:proceed-label="formatMessage(analyticsMessages.breakdownGroupsDelete)"
+		@proceed="confirmDelete"
+	/>
+	<div ref="optionContent" class="group flex min-w-0 flex-1 items-center gap-2">
+		<slot></slot>
+		<ButtonStyled type="outlined" size="small">
+			<button
+				class="!shadow-none transition-opacity"
+				:class="
+					activeGroup
+						? undefined
+						: 'md:opacity-0 md:group-focus-within:opacity-100 md:group-hover:opacity-100'
+				"
+				type="button"
+				:aria-label="formatMessage(analyticsMessages.breakdownGroupsButton)"
+				:aria-expanded="isMenuOpen"
+				aria-haspopup="menu"
+				@click.stop="toggleMenu"
+				@keydown.enter.stop
+				@keydown.space.stop
+			>
+				<span class="max-w-32 truncate">
+					{{ activeGroup?.name ?? formatMessage(analyticsMessages.breakdownGroupsButton) }}
+				</span>
+				<ChevronRightIcon />
+			</button>
+		</ButtonStyled>
+	</div>
+
+	<Teleport to="#teleports">
+		<Transition
+			enter-active-class="transition-opacity duration-150"
+			leave-active-class="transition-opacity duration-150"
+			enter-from-class="opacity-0"
+			leave-to-class="opacity-0"
+		>
+			<div
+				v-if="isMenuOpen"
+				ref="submenu"
+				data-multi-select-submenu
+				class="fixed z-[10000] w-64 overflow-hidden rounded-xl border border-solid border-surface-5 bg-surface-4 text-primary shadow-2xl"
+				:style="submenuStyle"
+				role="menu"
+				@mousedown.stop
+				@click.stop
+				@keydown.esc.stop="closeMenu"
+			>
+				<button
+					type="button"
+					class="menu-row"
+					:class="{ 'text-brand': isNoGroupingActive }"
+					@click="selectGroup(null)"
+				>
+					<span class="min-w-0 flex-1 text-left">
+						{{ formatMessage(analyticsMessages.breakdownGroupsNoGrouping) }}
+					</span>
+					<CheckIcon v-if="isNoGroupingActive" />
+				</button>
+				<div
+					v-for="group in groups"
+					:key="group.id"
+					class="group/menu-item flex items-center hover:bg-surface-5"
+				>
+					<button
+						type="button"
+						class="menu-row min-w-0 flex-1"
+						:class="{ 'text-brand': isGroupActive(group) }"
+						@click="selectGroup(group)"
+					>
+						<span class="min-w-0 flex-1 truncate text-left">{{ group.name }}</span>
+						<CheckIcon v-if="isGroupActive(group)" class="shrink-0" />
+					</button>
+					<button
+						type="button"
+						class="icon-action"
+						:aria-label="formatMessage(analyticsMessages.breakdownGroupsEdit)"
+						@click.stop="editGroup(group, $event)"
+					>
+						<PencilIcon />
+					</button>
+					<button
+						type="button"
+						class="icon-action hover:!text-red"
+						:aria-label="formatMessage(analyticsMessages.breakdownGroupsDelete)"
+						@click.stop="requestDelete(group, $event)"
+					>
+						<TrashIcon />
+					</button>
+				</div>
+				<button
+					type="button"
+					class="menu-row border-0 border-t border-solid border-surface-5 text-brand"
+					@click="createGroup"
+				>
+					<PlusIcon />
+					<span>{{ formatMessage(analyticsMessages.breakdownGroupsCreate) }}</span>
+				</button>
+			</div>
+		</Transition>
+	</Teleport>
+</template>
+
+<script setup lang="ts">
+import { CheckIcon, ChevronRightIcon, PencilIcon, PlusIcon, TrashIcon } from '@modrinth/assets'
+import { ButtonStyled, ConfirmModal, useVIntl } from '@modrinth/ui'
+
+import type {
+	AnalyticsActiveBreakdownGroup,
+	AnalyticsBreakdownGroup,
+	AnalyticsBreakdownPreset,
+} from '~/providers/analytics/analytics'
+import { injectAnalyticsDashboardContext } from '~/providers/analytics/analytics'
+
+import { analyticsMessages } from '../analytics-messages'
+
+type Breakdown = Exclude<AnalyticsBreakdownPreset, 'none'>
+
+const SUBMENU_GAP = 8
+const VIEWPORT_MARGIN = 8
+const SUBMENU_WIDTH = 256
+const OPEN_SUBMENU_EVENT = 'analytics-breakdown-group-submenu-open'
+
+const props = defineProps<{
+	breakdown: Breakdown
+	selected: boolean
+	activeGroup: AnalyticsActiveBreakdownGroup | null
+}>()
+const emit = defineEmits<{
+	activate: [breakdown: Breakdown]
+	selectGroup: [group: AnalyticsBreakdownGroup | null]
+	create: [breakdown: Breakdown, event?: MouseEvent]
+	edit: [group: AnalyticsBreakdownGroup, event?: MouseEvent]
+}>()
+
+const { breakdownGroups, deleteBreakdownGroup } = injectAnalyticsDashboardContext()
+const { formatMessage } = useVIntl()
+const optionContent = ref<HTMLElement | null>(null)
+const submenu = ref<HTMLElement | null>(null)
+const isMenuOpen = ref(false)
+const submenuStyle = ref({ left: '0px', top: '0px' })
+const deleteModal = ref<InstanceType<typeof ConfirmModal> | null>(null)
+const pendingDeleteGroup = ref<AnalyticsBreakdownGroup | null>(null)
+const menuId = Symbol('breakdown-group-submenu')
+
+const groups = computed(() =>
+	breakdownGroups.value.filter((group) => group.breakdown === props.breakdown),
+)
+const activeGroup = computed(() => {
+	if (!props.selected || props.activeGroup?.breakdown !== props.breakdown) return null
+	return groups.value.find((group) => group.id === props.activeGroup?.groupId) ?? null
+})
+const isNoGroupingActive = computed(() => props.selected && activeGroup.value === null)
+const deleteTitle = computed(() =>
+	formatMessage(analyticsMessages.breakdownGroupsDeleteTitle, {
+		name: pendingDeleteGroup.value?.name ?? '',
+	}),
+)
+
+function isGroupActive(group: AnalyticsBreakdownGroup) {
+	return activeGroup.value?.id === group.id
+}
+
+function selectGroup(group: AnalyticsBreakdownGroup | null) {
+	emit('selectGroup', group)
+	closeMenu()
+}
+
+function openMenu() {
+	if (!isMenuOpen.value) {
+		window.dispatchEvent(new CustomEvent(OPEN_SUBMENU_EVENT, { detail: menuId }))
+		isMenuOpen.value = true
+	}
+	updateMenuPosition()
+	nextTick(updateMenuPosition)
+}
+
+function closeMenu() {
+	isMenuOpen.value = false
+}
+
+function toggleMenu() {
+	if (isMenuOpen.value) {
+		closeMenu()
+	} else {
+		openMenu()
+	}
+}
+
+function updateMenuPosition() {
+	if (!isMenuOpen.value || typeof window === 'undefined') return
+
+	const anchor = optionContent.value?.closest<HTMLElement>('[role="option"]') ?? optionContent.value
+	if (!anchor) return
+
+	const anchorRect = anchor.getBoundingClientRect()
+	const submenuRect = submenu.value?.getBoundingClientRect()
+	const submenuWidth = submenuRect?.width ?? SUBMENU_WIDTH
+	const submenuHeight = submenuRect?.height ?? 320
+	const viewport = window.visualViewport
+	const viewportLeft = viewport?.offsetLeft ?? 0
+	const viewportTop = viewport?.offsetTop ?? 0
+	const viewportRight = viewportLeft + (viewport?.width ?? window.innerWidth)
+	const viewportBottom = viewportTop + (viewport?.height ?? window.innerHeight)
+	const anchorLeft = anchorRect.left + viewportLeft
+	const anchorRight = anchorRect.right + viewportLeft
+	const anchorTop = anchorRect.top + viewportTop
+	const opensRight =
+		anchorRight + SUBMENU_GAP + submenuWidth + VIEWPORT_MARGIN <= viewportRight ||
+		anchorLeft - submenuWidth - SUBMENU_GAP < viewportLeft + VIEWPORT_MARGIN
+	const preferredLeft = opensRight
+		? anchorRight + SUBMENU_GAP
+		: anchorLeft - submenuWidth - SUBMENU_GAP
+	const maxLeft = Math.max(
+		viewportLeft + VIEWPORT_MARGIN,
+		viewportRight - submenuWidth - VIEWPORT_MARGIN,
+	)
+	const maxTop = Math.max(
+		viewportTop + VIEWPORT_MARGIN,
+		viewportBottom - submenuHeight - VIEWPORT_MARGIN,
+	)
+
+	submenuStyle.value = {
+		left: `${Math.min(Math.max(viewportLeft + VIEWPORT_MARGIN, preferredLeft), maxLeft)}px`,
+		top: `${Math.min(Math.max(viewportTop + VIEWPORT_MARGIN, anchorTop), maxTop)}px`,
+	}
+}
+
+function handleOtherSubmenuOpen(event: Event) {
+	if ((event as CustomEvent<symbol>).detail !== menuId) closeMenu()
+}
+
+function handleDocumentMouseDown(event: MouseEvent) {
+	const target = event.target
+	if (
+		isMenuOpen.value &&
+		target instanceof Node &&
+		!optionContent.value?.contains(target) &&
+		!submenu.value?.contains(target)
+	) {
+		closeMenu()
+	}
+}
+
+function createGroup(event: MouseEvent) {
+	closeMenu()
+	emit('activate', props.breakdown)
+	emit('create', props.breakdown, event)
+}
+
+function editGroup(group: AnalyticsBreakdownGroup, event: MouseEvent) {
+	closeMenu()
+	emit('edit', group, event)
+}
+
+function requestDelete(group: AnalyticsBreakdownGroup, event: MouseEvent) {
+	pendingDeleteGroup.value = group
+	closeMenu()
+	deleteModal.value?.show(event)
+}
+
+function confirmDelete() {
+	if (pendingDeleteGroup.value) {
+		if (isGroupActive(pendingDeleteGroup.value)) emit('selectGroup', null)
+		deleteBreakdownGroup(pendingDeleteGroup.value.id)
+	}
+	pendingDeleteGroup.value = null
+}
+
+onMounted(() => {
+	window.addEventListener(OPEN_SUBMENU_EVENT, handleOtherSubmenuOpen)
+	window.addEventListener('resize', updateMenuPosition)
+	window.addEventListener('scroll', updateMenuPosition, true)
+	document.addEventListener('mousedown', handleDocumentMouseDown)
+})
+
+onBeforeUnmount(() => {
+	window.removeEventListener(OPEN_SUBMENU_EVENT, handleOtherSubmenuOpen)
+	window.removeEventListener('resize', updateMenuPosition)
+	window.removeEventListener('scroll', updateMenuPosition, true)
+	document.removeEventListener('mousedown', handleDocumentMouseDown)
+})
+</script>
+
+<style scoped>
+.menu-row {
+	display: flex;
+	width: 100%;
+	align-items: center;
+	gap: 0.625rem;
+	border: 0;
+	background: transparent;
+	padding: 0.75rem 1rem;
+	color: inherit;
+	box-shadow: none;
+}
+
+.menu-row:hover,
+.menu-row:focus-visible {
+	background: var(--surface-5);
+}
+
+.menu-row svg,
+.icon-action svg {
+	width: 1.25rem;
+	height: 1.25rem;
+}
+
+.icon-action {
+	display: flex;
+	flex-shrink: 0;
+	align-items: center;
+	justify-content: center;
+	border: 0;
+	background: transparent;
+	padding: 0.5rem;
+	color: var(--color-secondary);
+	box-shadow: none;
+}
+
+.icon-action:hover,
+.icon-action:focus-visible {
+	color: var(--color-contrast);
+}
+</style>
diff --git a/apps/frontend/src/components/analytics-dashboard/query-builder/index.vue b/apps/frontend/src/components/analytics-dashboard/query-builder/index.vue
index 1d43dbd9fb..f8f89d7ba9 100644
--- a/apps/frontend/src/components/analytics-dashboard/query-builder/index.vue
+++ b/apps/frontend/src/components/analytics-dashboard/query-builder/index.vue
@@ -1,5 +1,6 @@
 <template>
 	<div class="md:pl-1">
+		<BreakdownGroupModal ref="breakdownGroupModal" @save="saveBreakdownGroup" />
 		<div class="flex flex-wrap items-center gap-2 md:hidden">
 			<MultiSelect
 				v-if="showProjectRow"
@@ -156,8 +157,8 @@
 				class="min-w-0 max-w-full"
 				:options="breakdownOptions"
 				:max-height="QUERY_BUILDER_DROPDOWN_MAX_HEIGHT"
-				:dropdown-width="QUERY_BUILDER_DROPDOWN_MIN_WIDTH"
-				:dropdown-min-width="QUERY_BUILDER_DROPDOWN_MIN_WIDTH"
+				:dropdown-width="'20rem'"
+				:dropdown-min-width="'20rem'"
 				:trigger-class="analyticsQueryChipTriggerClass"
 				fit-content
 				checkbox-position="right"
@@ -183,6 +184,24 @@
 						/>
 					</div>
 				</template>
+				<template #option="{ item, selected }">
+					<BreakdownGroupOptionMenu
+						:breakdown="item.value"
+						:selected="selected"
+						:active-group="draftActiveBreakdownGroup"
+						@activate="ensureBreakdownSelected"
+						@select-group="selectBreakdownGroup(item.value, $event)"
+						@create="openCreateBreakdownGroup"
+						@edit="openEditBreakdownGroup"
+					>
+						<span
+							class="min-w-0 flex-1 truncate font-semibold leading-tight"
+							:class="selected ? 'text-contrast' : 'text-primary'"
+						>
+							{{ item.label }}
+						</span>
+					</BreakdownGroupOptionMenu>
+				</template>
 			</MultiSelect>
 
 			<QueryBuilderFilter
@@ -401,8 +420,8 @@
 									v-model="selectedBreakdownValue"
 									:options="breakdownOptions"
 									:max-height="QUERY_BUILDER_DROPDOWN_MAX_HEIGHT"
-									:dropdown-width="QUERY_BUILDER_DROPDOWN_MIN_WIDTH"
-									:dropdown-min-width="QUERY_BUILDER_DROPDOWN_MIN_WIDTH"
+									:dropdown-width="'24rem'"
+									:dropdown-min-width="'24rem'"
 									checkbox-position="right"
 									:placeholder="formatMessage(analyticsMessages.none)"
 									show-selection-actions
@@ -429,6 +448,24 @@
 											/>
 										</div>
 									</template>
+									<template #option="{ item, selected }">
+										<BreakdownGroupOptionMenu
+											:breakdown="item.value"
+											:selected="selected"
+											:active-group="draftActiveBreakdownGroup"
+											@activate="ensureBreakdownSelected"
+											@select-group="selectBreakdownGroup(item.value, $event)"
+											@create="openCreateBreakdownGroup"
+											@edit="openEditBreakdownGroup"
+										>
+											<span
+												class="min-w-0 flex-1 truncate font-semibold leading-tight"
+												:class="selected ? 'text-contrast' : 'text-primary'"
+											>
+												{{ item.label }}
+											</span>
+										</BreakdownGroupOptionMenu>
+									</template>
 								</MultiSelect>
 							</div>
 						</div>
@@ -469,6 +506,8 @@ import {
 	MAX_ANALYTICS_BREAKDOWN_PRESETS,
 } from '~/components/analytics-dashboard/analytics-route-query'
 import {
+	type AnalyticsActiveBreakdownGroup,
+	type AnalyticsBreakdownGroup,
 	type AnalyticsBreakdownPreset,
 	type AnalyticsDashboardProject,
 	type AnalyticsDashboardStat,
@@ -486,6 +525,8 @@ import {
 	formatAnalyticsGroupByLabel,
 	formatAnalyticsGroupBySelectedLabel,
 } from '../analytics-messages.ts'
+import BreakdownGroupModal from './BreakdownGroupModal.vue'
+import BreakdownGroupOptionMenu from './BreakdownGroupOptionMenu.vue'
 import DownloadsThresholdInput from './DownloadsThresholdInput.vue'
 import {
 	getAnalyticsStatsForBreakdown,
@@ -526,6 +567,7 @@ const {
 	selectedCustomTimeframeEndDate,
 	selectedGroupBy,
 	selectedBreakdowns,
+	activeBreakdownGroup,
 	selectedFilters,
 	activeStat,
 	showPreviousPeriod,
@@ -534,11 +576,37 @@ const {
 	queryResetToken,
 	refreshAnalyticsQuery,
 	setFetchRequest,
+	upsertBreakdownGroup,
+	setActiveBreakdownGroup,
 } = injectAnalyticsDashboardContext()
 const route = useRoute()
 const { formatMessage } = useVIntl()
 const { selectedTimeRange, selectedTimeframeDurationMinutes } = useSelectedAnalyticsTimeRange()
 const defaultQueryState = buildDefaultAnalyticsQueryBuilderState([])
+const breakdownGroupModal = ref<InstanceType<typeof BreakdownGroupModal> | null>(null)
+
+function openCreateBreakdownGroup(
+	breakdown: Exclude<AnalyticsBreakdownPreset, 'none'>,
+	event?: MouseEvent,
+) {
+	breakdownGroupModal.value?.show(breakdown, undefined, event)
+}
+
+function openEditBreakdownGroup(group: AnalyticsBreakdownGroup, event?: MouseEvent) {
+	breakdownGroupModal.value?.show(group.breakdown, group, event)
+}
+
+function saveBreakdownGroup(group: AnalyticsBreakdownGroup, activate: boolean) {
+	upsertBreakdownGroup(group)
+	if (activate) {
+		setActiveBreakdownGroup({ breakdown: group.breakdown, groupId: group.id })
+	}
+}
+
+function ensureBreakdownSelected(breakdown: Exclude<AnalyticsBreakdownPreset, 'none'>) {
+	if (selectedBreakdownValue.value.includes(breakdown)) return
+	selectedBreakdownValue.value = [...selectedBreakdownValue.value, breakdown]
+}
 
 function getProjectOption(
 	project: AnalyticsDashboardProject,
@@ -810,15 +878,25 @@ function selectUserProjectsMode() {
 }
 
 const draftSelectedBreakdowns = ref<AnalyticsSelectedBreakdowns>([...selectedBreakdowns.value])
+const draftActiveBreakdownGroup = ref<AnalyticsActiveBreakdownGroup | null>(
+	activeBreakdownGroup.value ? { ...activeBreakdownGroup.value } : null,
+)
 const isBreakdownSelectOpen = ref(false)
 
 const selectedBreakdownValue = computed<AnalyticsSelectedBreakdowns>({
 	get: () => draftSelectedBreakdowns.value,
 	set: (nextBreakdowns) => {
-		draftSelectedBreakdowns.value = getAnalyticsBreakdownPresetsForProjectSelection(
+		const normalizedBreakdowns = getAnalyticsBreakdownPresetsForProjectSelection(
 			nextBreakdowns.slice(0, MAX_ANALYTICS_BREAKDOWN_PRESETS),
 			selectedProjectIds.value,
 		)
+		draftSelectedBreakdowns.value = normalizedBreakdowns
+		if (
+			draftActiveBreakdownGroup.value &&
+			!normalizedBreakdowns.includes(draftActiveBreakdownGroup.value.breakdown)
+		) {
+			draftActiveBreakdownGroup.value = null
+		}
 	},
 })
 
@@ -829,14 +907,23 @@ watch(selectedBreakdowns, (nextBreakdowns) => {
 	draftSelectedBreakdowns.value = [...nextBreakdowns]
 })
 
+watch(activeBreakdownGroup, (nextActiveGroup) => {
+	if (isBreakdownSelectOpen.value) return
+	draftActiveBreakdownGroup.value = nextActiveGroup ? { ...nextActiveGroup } : null
+})
+
 function handleBreakdownSelectOpen() {
 	isBreakdownSelectOpen.value = true
 	draftSelectedBreakdowns.value = [...selectedBreakdowns.value]
+	draftActiveBreakdownGroup.value = activeBreakdownGroup.value
+		? { ...activeBreakdownGroup.value }
+		: null
 }
 
 function handleBreakdownSelectClose() {
 	isBreakdownSelectOpen.value = false
 	commitDraftSelectedBreakdowns()
+	commitDraftActiveBreakdownGroup()
 }
 
 function commitDraftSelectedBreakdowns() {
@@ -847,6 +934,27 @@ function commitDraftSelectedBreakdowns() {
 	}
 }
 
+function commitDraftActiveBreakdownGroup() {
+	const currentGroup = activeBreakdownGroup.value
+	const nextGroup = draftActiveBreakdownGroup.value
+	if (
+		currentGroup?.breakdown === nextGroup?.breakdown &&
+		currentGroup?.groupId === nextGroup?.groupId
+	) {
+		return
+	}
+	showPreviousPeriod.value = false
+	setActiveBreakdownGroup(nextGroup ? { ...nextGroup } : null)
+}
+
+function selectBreakdownGroup(
+	breakdown: Exclude<AnalyticsBreakdownPreset, 'none'>,
+	group: AnalyticsBreakdownGroup | null,
+) {
+	ensureBreakdownSelected(breakdown)
+	draftActiveBreakdownGroup.value = group ? { breakdown, groupId: group.id } : null
+}
+
 function areSelectedBreakdownsEqual(
 	left: readonly AnalyticsBreakdownPreset[],
 	right: readonly AnalyticsBreakdownPreset[],
diff --git a/apps/frontend/src/locales/en-US/index.json b/apps/frontend/src/locales/en-US/index.json
index 6073103af0..3a19673b4b 100644
--- a/apps/frontend/src/locales/en-US/index.json
+++ b/apps/frontend/src/locales/en-US/index.json
@@ -20,6 +20,81 @@
   "analytics.action.reset": {
     "message": "Reset"
   },
+  "analytics.action.save": {
+    "message": "Save"
+  },
+  "analytics.breakdown-groups.add-series": {
+    "message": "Add series"
+  },
+  "analytics.breakdown-groups.button": {
+    "message": "Group series"
+  },
+  "analytics.breakdown-groups.create": {
+    "message": "Create group"
+  },
+  "analytics.breakdown-groups.delete": {
+    "message": "Delete group"
+  },
+  "analytics.breakdown-groups.delete-description": {
+    "message": "This saved breakdown group will be permanently deleted from this browser."
+  },
+  "analytics.breakdown-groups.delete-title": {
+    "message": "Delete {name}?"
+  },
+  "analytics.breakdown-groups.edit": {
+    "message": "Edit group"
+  },
+  "analytics.breakdown-groups.group-name": {
+    "message": "Group name"
+  },
+  "analytics.breakdown-groups.group-name-placeholder": {
+    "message": "For example, Platform families"
+  },
+  "analytics.breakdown-groups.modal.create-title": {
+    "message": "Create breakdown group"
+  },
+  "analytics.breakdown-groups.modal.edit-title": {
+    "message": "Edit breakdown group"
+  },
+  "analytics.breakdown-groups.none": {
+    "message": "No grouping"
+  },
+  "analytics.breakdown-groups.other-description": {
+    "message": "{count, plural, one {# unassigned value} other {# unassigned values}}"
+  },
+  "analytics.breakdown-groups.remove-series": {
+    "message": "Remove series"
+  },
+  "analytics.breakdown-groups.select-values": {
+    "message": "Select values"
+  },
+  "analytics.breakdown-groups.series-name": {
+    "message": "Series name"
+  },
+  "analytics.breakdown-groups.series-values": {
+    "message": "Breakdown values"
+  },
+  "analytics.breakdown-groups.unavailable-value": {
+    "message": "{value} (not in current results)"
+  },
+  "analytics.breakdown-groups.validation.name-duplicate": {
+    "message": "A group with this name already exists for this breakdown."
+  },
+  "analytics.breakdown-groups.validation.name-required": {
+    "message": "Enter a group name."
+  },
+  "analytics.breakdown-groups.validation.series-name-duplicate": {
+    "message": "Custom series names must be unique."
+  },
+  "analytics.breakdown-groups.validation.series-name-required": {
+    "message": "Every custom series needs a name."
+  },
+  "analytics.breakdown-groups.validation.series-required": {
+    "message": "Add at least one custom series."
+  },
+  "analytics.breakdown-groups.validation.series-values-required": {
+    "message": "Assign at least one breakdown value to every custom series."
+  },
   "analytics.breakdown.country": {
     "message": "Country"
   },
diff --git a/apps/frontend/src/providers/analytics/analytics-types.ts b/apps/frontend/src/providers/analytics/analytics-types.ts
index 37d6b2a604..147bdee5df 100644
--- a/apps/frontend/src/providers/analytics/analytics-types.ts
+++ b/apps/frontend/src/providers/analytics/analytics-types.ts
@@ -47,6 +47,21 @@ export type AnalyticsBreakdownPreset =
 	| 'dependent_project_download'
 
 export type AnalyticsSelectedBreakdowns = Exclude<AnalyticsBreakdownPreset, 'none'>[]
+export type AnalyticsBreakdownGroupSeries = {
+	id: string
+	name: string
+	values: string[]
+}
+export type AnalyticsBreakdownGroup = {
+	id: string
+	name: string
+	breakdown: Exclude<AnalyticsBreakdownPreset, 'none'>
+	series: AnalyticsBreakdownGroupSeries[]
+}
+export type AnalyticsActiveBreakdownGroup = {
+	breakdown: Exclude<AnalyticsBreakdownPreset, 'none'>
+	groupId: string
+}
 export type AnalyticsDashboardStat = 'views' | 'downloads' | 'revenue' | 'playtime'
 export type AnalyticsGraphViewMode = 'line' | 'area' | 'bar'
 export type AnalyticsTableSortColumn =
diff --git a/apps/frontend/src/providers/analytics/analytics.ts b/apps/frontend/src/providers/analytics/analytics.ts
index a623a3913e..7c4089a9b4 100644
--- a/apps/frontend/src/providers/analytics/analytics.ts
+++ b/apps/frontend/src/providers/analytics/analytics.ts
@@ -80,6 +80,8 @@ import {
 	UNKNOWN_ORGANIZATION_NAME,
 } from './analytics-project-utils'
 import type {
+	AnalyticsActiveBreakdownGroup,
+	AnalyticsBreakdownGroup,
 	AnalyticsBreakdownPreset,
 	AnalyticsDashboardFilterOptions,
 	AnalyticsDashboardPercentChanges,
@@ -109,6 +111,9 @@ export {
 	getProjectIdsMatchingStatusFilter,
 } from './analytics-project-utils'
 export type {
+	AnalyticsActiveBreakdownGroup,
+	AnalyticsBreakdownGroup,
+	AnalyticsBreakdownGroupSeries,
 	AnalyticsBreakdownPreset,
 	AnalyticsDashboardFilterOptions,
 	AnalyticsDashboardPercentChanges,
@@ -186,6 +191,12 @@ export interface AnalyticsDashboardContextValue {
 	selectedGroupBy: Ref<AnalyticsGroupByPreset>
 	analyticsAllTimeStartDate: ComputedRef<Date>
 	selectedBreakdowns: Ref<AnalyticsSelectedBreakdowns>
+	breakdownGroups: Ref<AnalyticsBreakdownGroup[]>
+	activeBreakdownGroup: Ref<AnalyticsActiveBreakdownGroup | null>
+	resolvedActiveBreakdownGroup: ComputedRef<AnalyticsBreakdownGroup | null>
+	upsertBreakdownGroup: (group: AnalyticsBreakdownGroup) => void
+	deleteBreakdownGroup: (groupId: string) => void
+	setActiveBreakdownGroup: (activeGroup: AnalyticsActiveBreakdownGroup | null) => void
 	selectedFilters: Ref<AnalyticsSelectedFilters>
 	queryRefreshTimestamp: Ref<number>
 	queryResetToken: Ref<number>
@@ -315,6 +326,8 @@ export function createAnalyticsDashboardContext(
 	)
 	const selectedGroupBy = ref<AnalyticsGroupByPreset>(initialQueryState.selectedGroupBy)
 	const selectedBreakdowns = ref<AnalyticsSelectedBreakdowns>(initialQueryState.selectedBreakdowns)
+	const breakdownGroups = ref<AnalyticsBreakdownGroup[]>([])
+	const activeBreakdownGroup = ref<AnalyticsActiveBreakdownGroup | null>(null)
 	const selectedFilters = ref<AnalyticsSelectedFilters>(initialQueryState.selectedFilters)
 	const queryRefreshTimestamp = ref(Date.now())
 	const queryResetToken = ref(0)
@@ -324,6 +337,64 @@ export function createAnalyticsDashboardContext(
 	let revenueHourlyGroupByBeforeOverride: AnalyticsGroupByPreset | null = null
 	let mobileLayoutMedia: MediaQueryList | null = null
 
+	const resolvedActiveBreakdownGroup = computed<AnalyticsBreakdownGroup | null>(() => {
+		const activeGroup = activeBreakdownGroup.value
+		if (!activeGroup || !selectedBreakdowns.value.includes(activeGroup.breakdown)) return null
+		return (
+			breakdownGroups.value.find(
+				(group) => group.id === activeGroup.groupId && group.breakdown === activeGroup.breakdown,
+			) ?? null
+		)
+	})
+
+	function resetGraphDatasetSelection() {
+		hiddenGraphDatasetIds.value = []
+		hasExplicitGraphDatasetSelection.value = false
+		selectedGraphDatasetIds.value = []
+	}
+
+	function setActiveBreakdownGroup(nextActiveGroup: AnalyticsActiveBreakdownGroup | null) {
+		const current = activeBreakdownGroup.value
+		if (
+			current?.breakdown === nextActiveGroup?.breakdown &&
+			current?.groupId === nextActiveGroup?.groupId
+		) {
+			return
+		}
+		activeBreakdownGroup.value = nextActiveGroup
+		resetGraphDatasetSelection()
+	}
+
+	function upsertBreakdownGroup(group: AnalyticsBreakdownGroup) {
+		const groupIndex = breakdownGroups.value.findIndex((candidate) => candidate.id === group.id)
+		if (groupIndex === -1) {
+			breakdownGroups.value = [...breakdownGroups.value, group]
+		} else {
+			const nextGroups = [...breakdownGroups.value]
+			nextGroups[groupIndex] = group
+			breakdownGroups.value = nextGroups
+		}
+		if (activeBreakdownGroup.value?.groupId === group.id) {
+			resetGraphDatasetSelection()
+		}
+	}
+
+	function deleteBreakdownGroup(groupId: string) {
+		breakdownGroups.value = breakdownGroups.value.filter((group) => group.id !== groupId)
+		if (activeBreakdownGroup.value?.groupId === groupId) {
+			setActiveBreakdownGroup(null)
+		}
+	}
+
+	watch(selectedBreakdowns, (nextBreakdowns) => {
+		if (
+			activeBreakdownGroup.value &&
+			!nextBreakdowns.includes(activeBreakdownGroup.value.breakdown)
+		) {
+			setActiveBreakdownGroup(null)
+		}
+	})
+
 	function syncMobileLayoutState() {
 		isMobileLayout.value = mobileLayoutMedia?.matches ?? false
 	}
@@ -707,7 +778,7 @@ export function createAnalyticsDashboardContext(
 			selectedProjectIds.value,
 		)
 
-		return isQueryBuilderDefault && isGraphDefault
+		return isQueryBuilderDefault && isGraphDefault && activeBreakdownGroup.value === null
 	})
 	const isRevenueTimeframeAvailable = computed(
 		() =>
@@ -1867,6 +1938,7 @@ export function createAnalyticsDashboardContext(
 		selectedCustomTimeframeEndDate.value = defaultQueryState.selectedCustomTimeframeEndDate
 		selectedGroupBy.value = defaultQueryState.selectedGroupBy
 		selectedBreakdowns.value = defaultQueryState.selectedBreakdowns
+		setActiveBreakdownGroup(null)
 		selectedFilters.value = defaultQueryState.selectedFilters
 		activeStat.value = defaultGraphState.activeStat
 		activeGraphViewMode.value = defaultGraphState.activeGraphViewMode
@@ -1940,6 +2012,12 @@ export function createAnalyticsDashboardContext(
 		selectedGroupBy,
 		analyticsAllTimeStartDate,
 		selectedBreakdowns,
+		breakdownGroups,
+		activeBreakdownGroup,
+		resolvedActiveBreakdownGroup,
+		upsertBreakdownGroup,
+		deleteBreakdownGroup,
+		setActiveBreakdownGroup,
 		selectedFilters,
 		queryRefreshTimestamp,
 		queryResetToken,
diff --git a/packages/ui/src/components/base/MultiSelect.vue b/packages/ui/src/components/base/MultiSelect.vue
index 25a19b715d..f3a62c54bf 100644
--- a/packages/ui/src/components/base/MultiSelect.vue
+++ b/packages/ui/src/components/base/MultiSelect.vue
@@ -1205,6 +1205,7 @@ function handleDropdownKeydown(event: KeyboardEvent) {
 	switch (event.key) {
 		case 'Escape':
 			event.preventDefault()
+			event.stopPropagation()
 			closeDropdown()
 			break
 		case 'ArrowDown':
@@ -1355,7 +1356,7 @@ onClickOutside(
 	() => {
 		closeDropdown()
 	},
-	{ ignore: [triggerRef, containerRef, '.v-popper__popper'] },
+	{ ignore: [triggerRef, containerRef, '.v-popper__popper', '[data-multi-select-submenu]'] },
 )
 
 onMounted(() => {