Brian Boyd - You can do this already, but slightly differently than you're currently thinking about it.
There's a feature in the campaign canvas called "move to campaign". By setting up your different 'levels' as separate campaigns, you can then move people between them using the 'move to campaign'. It makes reporting a little bit tricky but keeps everything much cleaner, smaller and more manageable.
Also - you have to set up wait steps, usually .01 hours long, as a place for people to "land" from the Move to Campaign step.