Expression to Get Min / Max value of group

[#1]

Hello There,

I have a pivot table with a dimenssion Grouped by certian period of time:  [Year|Quarter|Month|Week]. I am trying to count when a MemberId was registered during the period in regard based on Activation / Expiration Dates (Com_DateActivated,Com_DateRealEnd) . I have the below expression:

=Count({< [Com_DateActivated] = {'<=$(Aggr(Max(CalendarDate),Period))'}, [Com_DateRealEnd] = {'>=$(Aggr(Min(CalendarDate),Period))'} >}DISTINCT Com_MemberId)

The problem is that it takes into consideration the Min and Max value of the whole dimmension, as below shown:

Jan-09	240,876
Feb-09	240,876
Mar-09	240,876

Instead of the group, which is  Iam trying to do.

Jan-09	240,876
Feb-09	280,805
Mar-09	300,542

Any idea how to solve this?

Thank in advance.

Best Regards

Octavio Melo