How to Merge Groups and Apply a Filter

Click on the "People" tab in the admin panel of the event

Click "Groups"

Select which two groups you want to merge in the event

Once selected click on the "Merge" option

From here you can provide the new "Group name"

Once the "Group name" is provided you can then apply the "Rules from" option to that group from this drop-down

Once this has been done click on the "Save" option and it will be saved in the event accordingly