To Do Widget - Select Alternate Task List

I have multiple To Do lists (work, personal and project) and so using the iOS widget I’d like to see the work list which is full of things to do. But I can only see Tasks in this widget and that is empty. I’d like either to have all tasks from my various lists appear in the Tasks as one comprehensive set or select my work tasks to appear in the widget display rather than the empty tasks. Am I missing a set up trick?