Follow these steps to create a Group Report.
On the Crystal Dashboard, using the top menu, navigate to the "Reports" page:

Scroll down to find "Group Report" and select "Build Report"

Fill out your Group Name, I've filled this one out as "Example Group" and search for the users you'd like to add to the report. You can see here I've selected Walter, Greg, Drew and James. Now select "NEXT"
NOTE: in order to add someone to a report, they will need to have a personality profile created either by taking an assessment themselves or by you predicting their personality using the Chrome Extension.

Select "BUILD REPORT"

This report will give you insights into how the group can work better together. See a portion of the report I created below:

If you'd like to see what the full report looks like, check out the sample Group Report.