Rolling Quarter

[#1]

I am trying to do rolling quarters for the following data -

So, if I have selected Nov 2015, the result for both would be:　 646,718,034 (accumulating all of the yellow numbers).

this is the code I am using for Rolling 12 months:

=Num(Sum({<[Account Description] = {'Total COGS'}, MonthYear = {"$(='>' & Date(AddMonths(Max(MonthYear), -12)) & '<=' & Date(Max(MonthYear)))"}, Year, Month, Quarter>} Actual),'#,##0')

I’ve tried modifying this code, but am getting the WRONG number:　 768,163,421

=Num(Sum({<[Account Description] = {'Total COGS'},
MonthYear = {"$(='>' & Date(AddYears(QuarterStart(Max(MonthYear)), -1)) & '<=' & Date(Max(MonthYear)))"}, Year, Month, Quarter>}
Actual),'#,##0')

Also, when I select Sep 2015 (the end month of the quarter (Mar, Jun, Sep, Dec) – it shouldn’t go back one quarter).　 The values should be (instead they equal the value of the quarter before):

　

Mar 2015 = 649,309,604

Jun 2015 = 649,320,387

Sep 2015 = 646,718,034

Nov 2015 = 646,718,034

Dec 2015 = 632,718,241

　

Does anyone know of a solution?　

Thank you for any assistance you can offer.

Kelly

stalwar1‌