I have been struggling to compare column values in a SSRS matrix (pivot table), but finally found a way around it.
My solution is rather simple, but it works.
Here is a simple example of the Matrix:
For example, I would like to compare the M2 value with M1 (15 vs 10) etc.
My initial thought was to use the ‘Previous’ function, but that did not seem to work, as it showed the previous ROW instead of COLUMN value.
However, you can add a group name to the function (it is not documented in Visual Studio, but it works) where you add the Column group name like so:
This way you get the previous value from a column and can compare the two.