You can try a set analysis expression. Suppose you now have sum(Sales) as expression. You can change that to sum({<Month={'<=$(=max({<Year={$(=max(Year))}>}Month))'}>}Sales). If you select 2012 and 2011 in the field Year and 2012 only has data for january then 2011 will also show only data for january. BTW, the Month field needs to be numeric of <= won't work (creating a month from a date with Month(MyDate) will create a usably month field).
You can try a set analysis expression. Suppose you now have sum(Sales) as expression. You can change that to sum({<Month={'<=$(=max({<Year={$(=max(Year))}>}Month))'}>}Sales). If you select 2012 and 2011 in the field Year and 2012 only has data for january then 2011 will also show only data for january. BTW, the Month field needs to be numeric of <= won't work (creating a month from a date with Month(MyDate) will create a usably month field).
