So i had this question posted on the MSDN Analysis Server Forum and got some help.

All I was trying to do was evaluate the currentmember of the the Dim Date FCSL_YM hierarchy and check if that member matched the current year month.

The syntax i was looking for was (in case someone ever needs help with this)

[Dim Date].[FSCL_YM].CURRENTMEMBER.UNIQUE_NAME =

"[Dim Date].[FSCL_YM].[Month Nm].&["+Format(now(), "yyyy")+"]&["+Format(now(), "%M")+"]"

Got my calculation working now with the above embedded in a case statement.