Hi figured this one out for you because i wanted to use it myself.
Make your background drag-dropable then pin all your buttons and contents to the backround.
Now restrict the x movement of your background. I did it by doing this :
If background X > or < than current X position then set back to current position.
(This will let you be able to scroll vertically but restricting it horisontally.
Now just restrict your vertical max and minimum so that it cannot be dragged out of the layout as well.
Hope this helps its a hack but it works .