Using LiveData and Firebase database

Question

My firebase database looks like this:

Chats
 ----{userId1}
    ------{userId2 : true}
    ------{userId3 : true}
 ----{userId2}
    ------{userId1 : true}
    ------{userId3 : true}
Users
 -----{userId1}
     ---{...}
 -----{userId2}
     ---{...}
 -----{userId3}
     ---{...}

So i want to do basically is list a users chat, for example userId1 who is chatting with userId2 and userId3. This is how im doing it in the ViewModel:

public LiveData<List<Chats>> getChatList() {
DatabaseReference chatsRef = baseRef.child("Chats").child(getCurrentUser);
    FirebaseLiveData chatsLivedata = new FirebaseLiveData(chatsRef);
    return Transformations.map(chatsLivedata, new Function<DataSnapshot, List<Chats>>() {
        @Override
        public List<Chats> apply(DataSnapshot dataSnapshot) {
            List<Chats> chatsList = new ArrayList<>();
            if (dataSnapshot.exists()){
                for (DataSnapshot snapshot: dataSnapshot.getChildren()){
                    usersRef.child(snapshot.getKey()).addValueForSingleEventListener(new ValueEventListener{

    @Override
    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
        Chats chat = dataSnapshot.getValue(Chats.class);
          chatsList.add(chat);

    }

    @Override
    public void onCancelled(@NonNull DatabaseError databaseError) {
    }
}
                }
            }
           
            return chatsList;
        }
    });

}

But the LiveData always return 0 chat item. I understand that its due to the asynchronous nature of firebase, so pls, how else can i implement this? All i want to do is use key under the Chats node to get a node under Users node thanks.