How do I view a list of users *not* assigned to a user group

We have all of our authoring collaborative spaces managed by User Groups. So when a new user is added to the platform, they need to be added to a user group before they do any edits or creation.

I'm sure I've missed a few people that are already on the platform.
 

How do I find a list of users that are not associated with any user group?

 

I tried search filters and tags, but there wasn't an option to filter by user group (so I could exclude that tag).

 

I looked in the User Guide, but didn't find anything promising there: https://help.3ds.com/2026x/English/DSDoc/EXP3DBasicsUserGroupsMap/exp3dbasicsusergroups-c-ov.htm

 

Thoughts?

My current best guess is to export a list of user groups and export a list of users to a spreadsheet and have ✨AI✨ compare the lists to see which users are missing from the user group member list. 

But I feel like this should be accomplishable in the platform natively, but I'm drawing blanks.