Add selected channels to group

Tiny feature request but it's always frustrated me that to add channels to an existing group, you have to type the group name again. I'd like to see either a menu item under "Group selected" - "Add selected to group > (list of existing groups)" or on the group selector context menu, or a list of existing names along with the text field. I don't care particularly how it's presented, I just want to be able to add channels to existing groups without having to retype the name.