Show entries without group

Is there an easy way (searching) to show entries without a group or without belonging to one of the groups in the group-tree?

I had entries with “groups = misc” and some without any group field. But “misc” wasn’t part of the group-tree.

Currently I have the workaround to activate the “groups” column in the table view and sort for them.

This feature has been proposed on the issue tracker:

We are currently right in the middle of a complete overhaul of the groups interface. Maybe this feature makes it in, but no promises.

JabRef 5.6–2022-04-25–5c9d898
Linux 5.4.0-113-generic amd64
Java 17.0.2
JavaFX 18+12

While I think this feature should show in the groups pane by default, I was able to create such a group manually, using Regular Expressions (RegEx): groups != .+

See here for info about JabRefs RegEx capabilities: