Can submenu items be added to the Menu Bar or Button Bar?

is it possible to have sub-menu items on the 'Menu Bar'? .. i know you can link to another balsamiq file using the link, but all im really after is being able to show that there are a load of level 2 items underneath the level 1 item eg under 'File' we have 'New', 'Open', 'Save', 'Save as', 'Exit' etc. Similar suggestion for the Button Bar / Tab Bar.. (actually, this is where id really like to have this feature..)
Thanks! :)
Rich Hunt