You make a bunch of toolbar buttons which run Go TABGROUPLOAD="xyz" where xyz is the name of the group.
The video shows how to make toolbar buttons. It's only a few minutes long.
The only thing the video doesn't show is how to create sub-menus, but that's done in a similar way to creating new buttons: When in Customize mode, right-click the toolbar or menu and select New -> New Menu.
(Creating new buttons is done using New -> New Button in Customize mode. You then right-click the new button and choose Edit, type the command into it, click OK... You can drag it to wherever you want it. Not much more to it.)