MDX to find Last Year,Quarter Month Data with Current Data

Hi Experts ,
I am working on SSAS 2008 Cube .

I have a Measure Group "Fact_Revenue" Which has One Measure as[Measures].[Revenue_Amt].
I have Date Dimension ,With One Hierarchy .Example from my Existing Cube

[Date].[FiscalHierarchy].[FYYear]
[Date].[FiscalHierarchy].[FYSemester]
[Date].[FiscalHierarchy].[FYQuarter]
[Date].[FiscalHierarchy].[FYMonth]

Using SSAS cube as a Source I am creating PPS 2010 report .
I have Date filter on the Top of Report 

Requirement : I need to create 2 Calculated Measure in my Cube 
1)Current_Revenue
2)Old_Revenue
         
if FY2012 is selected from Date filter i.e "Current Member " then 
Current_Revenue=Revenue of FY2012 
Old_Revenue=    Revenue of FY2011

if Q1-2012 is selected then 
Current_Revenue=Revenue of Q1-2012 
Old_Revenue=    Revenue of Q1-2011


if MAR-2012 is selected then 
Current_Revenue=Revenue of MAR-2012 
Old_Revenue=    Revenue of MAR-2011

How could this be achieved ?