Since in the MRT, you cannot reference the path further than 2 levels up.
Given a path such as X:\MUSIC\ROCK\ACDC\Razors Edge\[P::-1] equivalent to [P]
[P::-1,1] equivalent to [P]
[P::-2] equivalent to [G]
[P::-2,1] equivalent to [G]
[P::-2,2] equivalent to [G][P]
I propose the double colon as a single colon is utilized in "Custom Columns" syntax.[P::1] would result in: MUSIC
[P::-4] would result in MUSIC
[P::2] would result in: ROCK
[P::1,2] would result in: MUSICROCK
[P::-1] would result in: Razors Edge
[P::-4,4] would result in: MUSICROCKACDCRazors Edge
etc.