I've been trying to mess around with calculated dimensions (to show the "of the mobile plans that have changed in the last X months" portion), and I have come up with this (still doesn't account for time, only plans that have EVER changed):
In addition to the calculated dimension, I need to show what the actual previous/current plan name and cost are. I think this will require a FirstSortedOrder() function to tell the abstract that I want the most recent plan or cost, and the most recent before that. Something like:
Right now, my calculated dimension isn't working, so my expression is also broken. Is this the way I should be going about the problem?