On the ATT uverse original remote they have a "back" button that goes back/up one menu screen

and

it has a "last channel" button for just going back to a previous channel.


However the way the Harmony 900 is setup is that you'd use the little button just below and to the left of the channel button for going back to the previous channel.

What button have you guys use to accomplish the "back" button feature without putting it on the soft buttons or touch screen? It would work more ergonomic if it was a hard button but I can't seem to decide where to put it.