diff --git a/lib/Db/TagMapper.php b/lib/Db/TagMapper.php
index d4096c1..4e65e4e 100644
--- a/lib/Db/TagMapper.php
+++ b/lib/Db/TagMapper.php
@@ -42,7 +42,7 @@ class TagMapper extends QBMapper {
 	 * @throws \OCP\AppFramework\Db\MultipleObjectsReturnedException
 	 * @throws DoesNotExistException
 	 */
-	public function findIncludingGroupfolder(int $groupFolderId, string $tagKey): Tag {
+	public function findIncludingGroupfolder(int $groupFolderId, string $tagKey): array {
 		/* @var $qb IQueryBuilder */
 		$qb = $this->db->getQueryBuilder();
 		$qb->select('*')
@@ -50,7 +50,7 @@ class TagMapper extends QBMapper {
 			->where($qb->expr()->eq('group_folder_id', $qb->createNamedParameter($groupFolderId, IQueryBuilder::PARAM_INT)))
 			->andWhere($qb->expr()->eq('tag_key', $qb->createNamedParameter($tagKey)))
 			->leftJoin('t', self::GROUP_FOLDERS_TABLENAME, 'g', $qb->expr()->andX(
-				$qb->expr()->eq('t.group_folder_id', 'g.id'),
+				$qb->expr()->eq('t.group_folder_id', 'g.folder_id'),
 			));
 
 		return $this->findOneQuery($qb);
@@ -75,6 +75,105 @@ class TagMapper extends QBMapper {
 		return $this->findEntities($qb);
 	}
 
+	/**
+	 * @param string $tagKey
+	 * @param string|null $tagValue
+	 * @return array
+	 */
+	public function findAllIncludingGroupfolder(string $tagKey, ?string $tagValue = null): array {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('*')
+			->from(self::TABLENAME, alias: "t")
+			->where($qb->expr()->eq('tag_key', $qb->createNamedParameter($tagKey)));
+
+		if(isset($tagValue)) {
+			$qb->andWhere($qb->expr()->eq('tag_value', $qb->createNamedParameter($tagValue)));
+		}
+
+		$qb->leftJoin('t', self::GROUP_FOLDERS_TABLENAME, 'g', $qb->expr()->andX(
+			$qb->expr()->eq('t.group_folder_id', 'g.folder_id'),
+		));
+
+		return $qb->executeQuery()->fetchAll();
+	}
+
+	/**
+	 * @param array $filters
+	 * @param array|null $additionalReturnTags
+	 * @return array
+	 */
+	private function findGroupfoldersWithTagsQueryBuilder(array $filters, array $additionalReturnTags = []): IQueryBuilder {
+		/* @var $qb IQueryBuilder */
+		$qb = $this->db->getQueryBuilder();
+		$qb->select('g.mount_point', 'g.quota', 'g.acl')
+			->selectAlias('g.folder_id', 'id')
+			->from(self::GROUP_FOLDERS_TABLENAME, alias: "g");
+
+		$index = 0;
+		foreach($filters as $filter) {
+			$alias = 'filter_' . $index;
+			$joinConditions = [
+				$qb->expr()->eq($alias . '.group_folder_id', 'g.folder_id'),
+				$qb->expr()->eq($alias . '.tag_key', $qb->createNamedParameter($filter["key"]))
+			];
+
+			if(isset($filter["value"])) {
+				$joinConditions[] = $qb->expr()->eq($alias . '.tag_value', $qb->createNamedParameter($filter["value"]));
+			}
+
+			$qb->innerJoin('g', self::TABLENAME, $alias, $qb->expr()->andX(...$joinConditions));
+
+			if(isset($filter["includeInOutput"]) && $filter["includeInOutput"] === true) {
+				$qb->selectAlias($alias . '.tag_value', $filter["key"]);
+			}
+
+			$index++;
+		}
+
+		$index = 0;
+		foreach($additionalReturnTags as $additionalReturnTag) {
+			$alias = 'additional_' . $index;
+
+			$qb->leftJoin('g', self::TABLENAME, $alias, $qb->expr()->andX(
+				$qb->expr()->eq($alias . '.group_folder_id', 'g.folder_id'),
+				$qb->expr()->eq($alias . '.tag_key', $qb->createNamedParameter($additionalReturnTag))
+			));
+
+			$qb->selectAlias($alias . '.tag_value', $additionalReturnTag);
+
+			$index++;
+		}
+
+		return $qb;
+	}
+
+	/**
+	 * @param array $filters [key: string, (value: string), (includeInOutput: bool)] filter pairs, result is only included if 
+	 * @param array|null $additionalReturnTags array of tags to return (if set, otherwise NULL)
+	 * @return array
+	 */
+	public function findGroupfoldersWithTags(array $filters, array $additionalReturnTags = []): array {
+		return $this->findGroupfoldersWithTagsQueryBuilder($filters, $additionalReturnTags)->executeQuery()->fetchAll();
+	}
+
+	/**
+	 * @param array $filters [key: string, (value: string), (includeInOutput: bool)] filter pairs, result is only included if 
+	 * @param array|null $additionalReturnTags array of tags to return (if set, otherwise NULL)
+	 * @return array
+	 */
+	public function findGroupfoldersWithTagsGenerator(array $filters, array $additionalReturnTags = []): \Generator {
+		$result = $this->findGroupfoldersWithTagsQueryBuilder($filters, $additionalReturnTags)->executeQuery();
+
+		try {
+			while ($row = $result->fetch()) {
+				yield $row;
+			}
+		} finally {
+			$result->closeCursor();
+		}
+	}
+
 	/**
 	 * @return Tag[]
 	 * @throws Exception
diff --git a/lib/Service/TagService.php b/lib/Service/TagService.php
index 0cbbb25..1885488 100644
--- a/lib/Service/TagService.php
+++ b/lib/Service/TagService.php
@@ -22,6 +22,18 @@ class TagService {
 		return $this->mapper->findAll($tagKey, $tagValue);
 	}
 
+	public function findAllIncludingGroupfolder(string $tagKey, ?string $tagValue = null): array {
+		return $this->mapper->findAllIncludingGroupfolder($tagKey, $tagValue);
+	}
+
+	public function findGroupfoldersWithTags(array $filters, array $additionalReturnTags = []): array {
+		return $this->mapper->findGroupfoldersWithTags($filters, $additionalReturnTags);
+	}
+
+	public function findGroupfoldersWithTagsGenerator(array $filters, array $additionalReturnTags = []): \Generator {
+		return $this->mapper->findGroupfoldersWithTagsGenerator($filters, $additionalReturnTags);
+	}
+
 	private function handleException(Exception $e, int $groupFolderId, string $tagKey): void {
 		if ($e instanceof DoesNotExistException ||
 			$e instanceof MultipleObjectsReturnedException) {