Selecting 'Item at Index'
Selecting 'Specific Index'
Adding the Variable 'Index to List'

Caveat being: I am very new to this and while that works for my needs I have no idea if that is the best or right way!

Thanks
JP

Here are two approaches:

You'll need a simple custom function, here's example code:

List<String> mergeList(
  List<String> list1,
  List<String> list2,
  List<String> list3,
) {

  List<String> result = [];

  result.addAll(list1);
  result.addAll(list2);
  result.addAll(list3);

  return result;

}

Just pass all the lists from the backend query to the function, then generate children from variable in the list view using the result.

The above is a function I personally use.

Below is a modified version of that function that might suit you better. It takes the list of documents from the backend query as a parameter, extracts the property that has the list of strings (nameList), and merges them all in to a single list in the result value:

List<String> extractListsAndMerge(List<Document> documents) {
  List<String> result = [];

  for (Document document in documents) {
    result.addAll(document.listPropertyName);
  }

  return result;
}

All you need to do is replace "listPropertyName" with the name of the property that has the string list - which in your case is nameList.

I haven't tested this one, but should be fine.