I can’t find an existing discussion about this either (not to say that there aren’t related threads out there) but what I can say is that this is not currently supported by the widget.
So, at this time, you would really need to do some customization to make this happen – and based on what you’re describing that would basically mean creating a new widget (albeit you might base it on the code of the existing list widget).
It would of course be great to hear back from you and see your final solution if you do press ahead with this. Remember also that you can suggest new features on our UserVoice page, which also lets other users indicate their support:
https://tribe.uservoice.com/forums/195723-feature-ideas