Retrieving data from more collections from firestore in flutter - dart

Question

I am retrieving data from a collection of "players" in my code in flutter project. I am right now building a listview from the data i am receiving through the code below. However, I would like to retrieve some more data, that would just need to be saved in the background and not used visually. However, I can't figure out how to retrieve the data, without having to visually show it with a widget.
I tried using the same procedure as the code showing here. I can only retrieve one collection at the time, and not both.
Can anyone point me in the direction of how to retrieve data without having to "show" it in the build widget?
Widget _buildBody(BuildContext context) {
return StreamBuilder<QuerySnapshot>(
stream: Firestore.instance.collection('Spillere').snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return LinearProgressIndicator();
return _buildList(context, snapshot.data.documents);
},
);
}
Widget _buildList(BuildContext context, List<DocumentSnapshot> snapshot) {
return ListView(
padding: const EdgeInsets.only(top: 10.0),
children: snapshot.map((data) => _buildListItem(context, data)).toList(),
);
}
Widget _buildListItem(BuildContext context, DocumentSnapshot data) {
final record = Record.fromSnapshot(data);
return Padding(
key: ValueKey(record.name),
padding: const EdgeInsets.all(5.0),
child: Container(
decoration: BoxDecoration(
border: Border.all(color: Colors.grey),
borderRadius: BorderRadius.circular(5.0),
),
child: ListTile(
title: Text(record.name + ": " + record.score.toString()),
trailing: new IconButton(icon: new Icon(isAdmin ? Icons.add : null, color: Colors.green),
onPressed: (){
if(isAdmin){
record.reference.updateData({'score': record.score + 1});
}
}
),
),
),
);
}