looking to compute difference between columnvalue in pivot view

[Rkota]

In this pivot view, I'm trying to compute the difference between the months for each line of the update range.  I'm looking to get the absolute value.  Here is the dimension and expression (just a simple count on the dimension shown in parenthesis.

 

the expression I'm using to compute totals by moth is not working - it includes all months.  Maybe my approach is wrong.

Sample for on month

Count({<Movemonth = {"$(='>=' & Date((AddMonths(Today(),-3)),'MMMMM'))"}>} unittranid)

Any help/tips to fix this issue would be greatly appreciated.

Thx

[sunny_talwar]

If you are looking to find the difference in Period & Period - 1 and Period - 1 & Period - 2 and Period - 2 & Period - 3 and so on... why do you want to use set analysis? What issue are you seeing with using Above()/Below()/After()/Before() functions? A more optimized way is to use The As-Of Table if you are seeing performance issue... but in this scenario, set analysis is not going to work.