1. Using the Custom Reports feature, select whatever Column headings you want to show. (I recommend choosing Groups as a Column as a check to make sure the logical filters were applied correctly so that no Groups show in the Groups column).

2. Next, create the Filter.

3. In the pull-down list, find Company: Groups.

4. Select "is Empty".

5. Click into the next cell to bring up the Groups table, and check-mark each Group name, then Run the report. It should be everyone that is not in a Group.