What would I have to edit in order to hide the 'up one level' button (the control with the eject icon that appears when you view music/pictures/movies etc)? I've looked at the source and it appears only to construct the listcontrol, however the XML files actually display it. I just don't know what to edit in order to hide the label control to navigate to the parent folder.

Check out the system/settings blade. You can enable/disable it there