Current state with latest updates

app/Services/Sitemaps/SitemapBuildService.php

@@ -42,6 +42,23 @@ final class SitemapBuildService
      */
     public function buildNamed(string $name, bool $force = false, bool $persist = true): ?array
     {
+        $groupFamilies = $this->groupFamilies($name);
+        if ($groupFamilies !== null) {
+            $built = $this->cache->remember(
+                $name,
+                fn (): string => $this->renderer->renderIndex($this->index->itemsForFamilies($groupFamilies)),
+                $force,
+                $persist,
+            );
+
+            return $built + [
+                'type' => SitemapTarget::TYPE_INDEX,
+                'url_count' => count($this->index->itemsForFamilies($groupFamilies)),
+                'shard_count' => 0,
+                'name' => $name,
+            ];
+        }
+
         $target = $this->shards->resolve($this->registry, $name);
 
         if ($target === null) {
@@ -111,6 +128,24 @@ final class SitemapBuildService
         ));
     }
 
+    /**
+     * @return list<string>|null
+     */
+    public function groupFamilies(string $name): ?array
+    {
+        $families = $this->index->activeGroupIndexes($this->enabledFamilies())[$name] ?? null;
+
+        return is_array($families) && $families !== [] ? $families : null;
+    }
+
+    /**
+     * @return array<string, list<string>>
+     */
+    public function enabledGroupIndexes(): array
+    {
+        return $this->index->activeGroupIndexes($this->enabledFamilies());
+    }
+
     private function renderTarget(SitemapTarget $target): string
     {
         if ($target->type === SitemapTarget::TYPE_INDEX) {
@@ -140,4 +175,4 @@ final class SitemapBuildService
 
         return count($target->builder->items());
     }
-}
+}