Rollup Calculations
By rolling up calculations, you can more easily analyze groups of categories within the same dimension. When you apply the rollup function, you create a new calculation that applies the rollup function (either add, minimum, maximum, or weighted average) defined for the measure used by the selected categories.
For example, the Course Pro line includes products from more than one category in Golf Equipment. You create a report that includes only the Course Pro products and then add a rollup calculation to determine the overall profit margin for each quarter.

When you drill up or drill down on one of the selected categories included in the rollup calculation, the calculation is recalculated.
You can perform rollup calculations on subsets.