You can do this with something like the following calculation:
IF [Order Date]<=today() AND datediff('month',[Order Date],today())=0 THEN "Current MTD"
ELSEIF [Order Date]<=dateadd('month',-1,today()) AND datediff('month',[Order Date],dateadd('month',-1,today()))=0 THEN "Past MTD"
Add this dimension to the view and then filter out the Filter section as this will capture data for all the dates that do not fall in the current or past MTD ranges.
Alex Kerin You might be right that we need to add this to a resource. I will take a stab at creating a KB internally to see if we can add it in the future.
Hope this helps,
Thank you Dan. Worked like a charm