Groups in item list not visible

I have a couple of databases in which groups are not appearing in the item list/file list. For example in the screenshot below I have a ‘Research’ database with multiple groups that do not appear in the item list.

In contrast I have another database (‘Committees’ in the screenshot below)that does display the groups in the item list.

Not sure why I can’t see the groups in some databases.

Running DEVONthink 3.0.1

Did you enable the option View > Show Only Documents for one of the databases?