We have designed several cubes and used this data for general
reporting. Our next step is to identify product trends. For example
we would like to identify products whose sales have declined the past
two months (or whatever time period we define). I'm thinking this
would require some sort of MDX query in form of this pseudocode:

if('AVG sales for current month' < 'AVG sales for last month'), '1'
else '2'

If this is the correct approach, I guess my question would be, how do
I get the MDX query to always return the data for the current month,
or the last month, etc.

Thanks in advance!