Is it possible to show all ungrouped references?

I have started working with JabRef not too long ago and it is working really well, but one thing is bugging me: I can’t see which refrences are not sorted in groups yet.

When I could create a group that shows me which ones are not sorted or highlight them in some way that would really speed up my working progress!!

Is there any possibility like this?

This is currently not possible and a feature request for it already exists: