Flutter & Firebase: Please add a function to get all sub-collection in a specific collection in the Flutter.

[SittiphanSittisak]

For example, I have collections A and B. A and B have sub-collections with the same name as C. I would like to get all sub-collections C in collection A.

For using this below will get all sub-collections C in collections A and B.
FirebaseFirestore.instance.collectionGroup('C').get()

For using this below must get big data before receiving sub-collection.

  CollectionReference collectionData = FirebaseFirestore.instance.collection('A');
  collectionData.get().then((value) {
    for (QueryDocumentSnapshot doc in value.docs) {
      collectionData
          .doc(doc.id)
          .collection('C')
          .get()
          .then((value) {});
    }
  });

Please add a function to get all sub-collection in a specific collection like
FirebaseFirestore.instance.collectionGroup('C', collectionReference: FirebaseFirestore.instance.collection('A')).get().