PreviousPeriod combined with IF or CASE

[Eric Hans van Wingerden 4]

Attached please find a DXP with a calculated column. I have a column in which I want the previous value of AMOUNT, so the value of Previous month, within a customer. In the example this works perfectly.

Max([Amount]) over (Intersect(PreviousPeriod([Month]),[Customer]))

However, What I really want is that the first month this column should just be the AMOUNT of the current Month:

If([Ranking]>1,Max([Amount]) over (Intersect(PreviousPeriod([Month]),[Customer])),[Amount])

 

it skips the second month

 

Am I doning something wrong YOur help would be appreciated!

[Gaia Paolini]

Try putting SN(...) around it:

SN(Max([Amount]) over (PreviousPeriod([Month])),[Amount])

SN replaces nulls with the second argument.