Get map data from Cloud Firestore

Question

I want to get map data from cloud Firestore,this is java code I need to access the same database in swift. I attached the java code and database structure picture for reference.

FirebaseFirestore db = FirebaseFirestore.getInstance();
    DocumentReference mDocRef = db.collection("hmdhAcademy").document("notifications");

    mDocRef.get().addOnCompleteListener(task -> {

        if ( task.isSuccessful() ) {

            DocumentSnapshot documentSnapshot = task.getResult();

            if ( documentSnapshot != null && documentSnapshot.exists() ){

                notificationList = (ArrayList) documentSnapshot.get("userNotifications");
                adapter = new NotificationAdapter(this,notificationList);
                mRecyclerView.setAdapter(adapter);
                alertDialog.dismiss();
            }
        }
        else {

            Toast.makeText(NotificationActivity.this,"Check Internet Connection",Toast.LENGTH_SHORT).show();
            alertDialog.dismiss();
        }

    });

if ( list.get(i) instanceof  HashMap ){

        final Intent intent = new Intent(mContext,NotificationDetail.class);

        String title = (String)((HashMap)list.get((list.size()-1)-i)).get("title");
        String body = (String)((HashMap)list.get((list.size()-1)-i)).get("body");
        String image = (String)((HashMap)list.get((list.size()-1)-i)).get("notiImage");
        String detail = (String)((HashMap)list.get((list.size()-1)-i)).get("detail");
}

I need the same title, body, notiImage and detail.

Please help me with that, I'm looking for an answer anywhere but failed.