Create calculated measure using PrevMember

Hello All,

I created calculated measure using PrevMember function.

([DimTime].[Year-Month].CurrentMember.PrevMember , [Measure].[SomeMeasure])

I browsed cube and previous members displayed correctly. When I applied year-month filter for that no results displayed. I want to get previous member(selected member's previous member) total value.

Any reason for this case??

Thanks in advance.