WSUS Groups are used as target groups in CSM for WSUS. You can use existing WSUS groups, or create new groups for CSM for WSUS. You can modify WSUS groups from WSUS management console:
1. Open Windows Server Update Services (wsus.msc) in start menu.
2. Navigate to Options and All computers. You can see a list of your current WSUS groups, or create a new by right clicking All Computers and select Create new group