Groups are used as a method to categorize attendees/users in an event. By merging the two groups, you can create one unit/group in the event.
How to merge groups
Go to the "People" tab in the admin panel of the event and navigate to "Groups"
Select which two groups you want to merge in the event and click "Merge."
From here, you can provide the new "Group name" and click "Ok"
You will see the merged group.
