On the iDrive systems there is a secret menu too, accessed by a certain amount of wiggling the iDrive controller in a certain order. I don't think anything comes up on the nav from this one. There is a service menu on the nav systems which is a seperate thing to the OBC menu.
Select "settings" then press and hold the "menu" button for a few seconds. This is how you enable the perspective view (if you didn't have it already enabled)