In Portal, go into the Players section.

1. Click New group.
2. Give your group a name.
3. If you want all players that are included in the group to play the same content, click the Playlist field and select a playlist. 
4. Click Save.

Add players to a group

1. In the Players section, click the padlock icon to enter edit mode.
2. Select any players to add to the group.
3. Drag-and-drop the players into the group.
4. Click the padlock icon again to close the edit mode.