Average of current month and previous month

[#1]

I'm trying to create a variable that takes the average of a metric (lodgements) for the current month and previous month.

This is the forumla I have so far. I'm not sure why it's not working. Can someone please assist? Thank you.

if(count(DISTINCT [Fin Period]) = 1, (sum({$ <[Fin Period] = {"<=$(vMaxFinPeriodComp)"} - {"<$(vMinFinPeriodComp)"},[Fin Year]=,[Fin Month]=, [Fin Week]=>}$(vLodgements)

vMinFinPeriodComp=

date(AddMonths(max([Fin Period]

),-1),'YYYYMM')

vMaxFinPeriodComp=

Max([Fin Period]

)

[er_mohit]

Try this

sum({<[Fin Year]=,[Fin Month]=, [Fin Week]=,

[Fin Period]={">=$(=addmonths(monthend(max([Fin Period]))+1,-2)) <=$(=max([Fin Period]))"}>}lodgements)