Restrict Customer name using calculated dimension

[#1]

Hi All

I have 3 columns

Customer YearMonth Revenue

I wanted to show the customers if the currentmonth - previous month revenue < 0

So how to do that on calculated dimension.??

I have an expression already calculating last three month sales.

So i need to do this in calculated dimension.. please help me..

[#2]

This should work if you have MonthID as a numeric field.If you dont use condition you use for current month.

if(aggr(Sum({<MonthID={"$(=Max(MonthID))"}>}Revenue)-Sum({<MonthID={"$(=Max(MonthID)-1)"}>}Revenue),Customer)<0,Customer)

Kiran.