I am not quite sure how to describe what I am trying to do (which doesn't help), but I will try my best.
My first level page has two sets of available navigation, generated from two TreeMultiselectFields in the CMS. I need a way of dynamically discovering if the current sub page is in one list of the other, and then generate the required list as navigation ont hat page too.
I was thinking I need to use Dataobject::get() and then run a comparison in the Controller class, but I am not really sure the best way to do this??