[Logs Explorer] Fix Namespace Custom Filter (#192677)

closes https://github.com/elastic/kibana/issues/191332

## 📝  Summary

This PR adds a new prop to the [Unified Field
List](93acc6f707/packages/kbn-unified-field-list/README.md (L5))
making it accept `additionalFilters` that applies to the `Available
Field List` as well as to the `Field Stats`

## 🎥 Demo


https://github.com/user-attachments/assets/f029fd2d-7bec-4a01-985e-2a94ce431f84

packages/kbn-unified-field-list/src/containers/unified_field_list_item/field_list_item.tsx

@@ -14,6 +14,7 @@ import { UiCounterMetricType } from '@kbn/analytics';
 import type { FieldsMetadataPublicStart } from '@kbn/fields-metadata-plugin/public';
 import { Draggable } from '@kbn/dom-drag-drop';
 import type { DataView, DataViewField } from '@kbn/data-views-plugin/public';
+import { Filter } from '@kbn/es-query';
 import type { SearchMode } from '../../types';
 import { FieldItemButton, type FieldItemButtonProps } from '../../components/field_item_button';
 import {
@@ -200,6 +201,10 @@ export interface UnifiedFieldListItemProps {
    * Item size
    */
   size: FieldItemButtonProps<DataViewField>['size'];
+  /**
+   * Custom filters to apply for the field list, ex: namespace custom filter
+   */
+  additionalFilters?: Filter[];
 }
 
 function UnifiedFieldListItemComponent({
@@ -223,6 +228,7 @@ function UnifiedFieldListItemComponent({
   groupIndex,
   itemIndex,
   size,
+  additionalFilters,
 }: UnifiedFieldListItemProps) {
   const [infoIsOpen, setOpen] = useState(false);
 
@@ -288,6 +294,7 @@ function UnifiedFieldListItemComponent({
           multiFields={multiFields}
           dataView={dataView}
           onAddFilter={addFilterAndClosePopover}
+          additionalFilters={additionalFilters}
         />
 
         {searchMode === 'documents' && multiFields && (

packages/kbn-unified-field-list/src/containers/unified_field_list_item/field_list_item_stats.tsx

@@ -27,10 +27,11 @@ export interface UnifiedFieldListItemStatsProps {
   dataView: DataView;
   multiFields?: Array<{ field: DataViewField; isSelected: boolean }>;
   onAddFilter: FieldStatsProps['onAddFilter'];
+  additionalFilters?: FieldStatsProps['filters'];
 }
 
 export const UnifiedFieldListItemStats: React.FC<UnifiedFieldListItemStatsProps> = React.memo(
-  ({ stateService, services, field, dataView, multiFields, onAddFilter }) => {
+  ({ stateService, services, field, dataView, multiFields, onAddFilter, additionalFilters }) => {
     const querySubscriberResult = useQuerySubscriber({
       data: services.data,
       timeRangeUpdatesType: stateService.creationOptions.timeRangeUpdatesType,
@@ -55,6 +56,11 @@ export const UnifiedFieldListItemStats: React.FC<UnifiedFieldListItemStatsProps>
       [services]
     );
 
+    const filters = useMemo(
+      () => [...(querySubscriberResult.filters ?? []), ...(additionalFilters ?? [])],
+      [querySubscriberResult.filters, additionalFilters]
+    );
+
     if (!hasQuerySubscriberData(querySubscriberResult)) {
       return null;
     }
@@ -63,7 +69,7 @@ export const UnifiedFieldListItemStats: React.FC<UnifiedFieldListItemStatsProps>
       <FieldStats
         services={statsServices}
         query={querySubscriberResult.query}
-        filters={querySubscriberResult.filters}
+        filters={filters}
         fromDate={querySubscriberResult.fromDate}
         toDate={querySubscriberResult.toDate}
         dataViewOrDataViewId={dataView}

packages/kbn-unified-field-list/src/containers/unified_field_list_sidebar/field_list_sidebar.tsx

@@ -50,6 +50,7 @@ export type UnifiedFieldListSidebarCustomizableProps = Pick<
   | 'onAddFilter'
   | 'onAddFieldToWorkspace'
   | 'onRemoveFieldFromWorkspace'
+  | 'additionalFilters'
 > & {
   /**
    * All fields: fields from data view and unmapped fields or columns from text-based search
@@ -168,6 +169,7 @@ export const UnifiedFieldListSidebarComponent: React.FC<UnifiedFieldListSidebarP
   onDeleteField,
   onToggleSidebar,
   additionalFieldGroups,
+  additionalFilters,
 }) => {
   const { dataViews, core } = services;
   const useNewFieldsApi = useMemo(
@@ -285,6 +287,7 @@ export const UnifiedFieldListSidebarComponent: React.FC<UnifiedFieldListSidebarP
             groupName === FieldsGroupNames.SelectedFields ||
             Boolean(selectedFieldsState.selectedFieldsMap[field.name])
           }
+          additionalFilters={additionalFilters}
         />
       </li>
     ),
@@ -304,6 +307,7 @@ export const UnifiedFieldListSidebarComponent: React.FC<UnifiedFieldListSidebarP
       onDeleteField,
       workspaceSelectedFieldNames,
       selectedFieldsState.selectedFieldsMap,
+      additionalFilters,
     ]
   );
 

packages/kbn-unified-field-list/src/containers/unified_field_list_sidebar/field_list_sidebar_container.tsx

@@ -117,6 +117,7 @@ const UnifiedFieldListSidebarContainer = memo(
         prependInFlyout,
         variant = 'responsive',
         onFieldEdited,
+        additionalFilters,
       } = props;
       const [stateService] = useState<UnifiedFieldListSidebarContainerStateService>(
         createStateService({ options: getCreationOptions() })
@@ -151,11 +152,16 @@ const UnifiedFieldListSidebarContainer = memo(
       const searchMode: SearchMode | undefined = querySubscriberResult.searchMode;
       const isAffectedByGlobalFilter = Boolean(querySubscriberResult.filters?.length);
 
+      const filters = useMemo(
+        () => [...(querySubscriberResult.filters ?? []), ...(additionalFilters ?? [])],
+        [querySubscriberResult.filters, additionalFilters]
+      );
+
       const { isProcessing, refetchFieldsExistenceInfo } = useExistingFieldsFetcher({
         disableAutoFetching: stateService.creationOptions.disableFieldsExistenceAutoFetching,
         dataViews: searchMode === 'documents' && dataView ? [dataView] : [],
         query: querySubscriberResult.query,
-        filters: querySubscriberResult.filters,
+        filters,
         fromDate: querySubscriberResult.fromDate,
         toDate: querySubscriberResult.toDate,
         services,

src/plugins/discover/public/application/main/components/layout/discover_layout.tsx

@@ -103,6 +103,8 @@ export function DiscoverLayout({ stateContainer }: DiscoverLayoutProps) {
     state.dataView!,
     state.isDataViewLoading,
   ]);
+  const customFilters = useInternalStateSelector((state) => state.customFilters);
+
   const dataState: DataMainMsg = useDataState(main$);
   const savedSearch = useSavedSearchInitial();
 
@@ -401,6 +403,7 @@ export function DiscoverLayout({ stateContainer }: DiscoverLayoutProps) {
                 onFieldEdited={onFieldEdited}
                 onDataViewCreated={stateContainer.actions.onDataViewCreated}
                 sidebarToggleState$={sidebarToggleState$}
+                additionalFilters={customFilters}
               />
             }
             mainPanel={

src/plugins/discover/public/application/main/components/sidebar/discover_sidebar_responsive.tsx

@@ -23,6 +23,7 @@ import {
   FieldsGroupNames,
 } from '@kbn/unified-field-list';
 import { calcFieldCounts } from '@kbn/discover-utils/src/utils/calc_field_counts';
+import { Filter } from '@kbn/es-query';
 import { PLUGIN_ID } from '../../../../../common';
 import { useDiscoverServices } from '../../../../hooks/use_discover_services';
 import { DataDocuments$ } from '../../state_management/discover_data_state_container';
@@ -127,6 +128,10 @@ export interface DiscoverSidebarResponsiveProps {
   fieldListVariant?: UnifiedFieldListSidebarContainerProps['variant'];
 
   sidebarToggleState$: BehaviorSubject<SidebarToggleState>;
+  /**
+   * Custom filters to apply for the field list, ex: namespace custom filter
+   */
+  additionalFilters?: Filter[];
 }
 
 /**
@@ -153,6 +158,7 @@ export function DiscoverSidebarResponsive(props: DiscoverSidebarResponsiveProps)
     onAddField,
     onRemoveField,
     sidebarToggleState$,
+    additionalFilters,
   } = props;
   const [sidebarState, dispatchSidebarStateAction] = useReducer(
     discoverSidebarReducer,
@@ -383,6 +389,7 @@ export function DiscoverSidebarResponsive(props: DiscoverSidebarResponsiveProps)
             onFieldEdited={onFieldEdited}
             prependInFlyout={prependDataViewPickerForMobile}
             additionalFieldGroups={additionalFieldGroups}
+            additionalFilters={additionalFilters}
           />
         ) : null}
       </EuiFlexItem>