In this step of the wizard, you enable and define custom rollup expressions.
This step is displayed only if you selected Custom rollups in the Select advanced options step of the wizard.
Enable custom rollups
Select to enable custom rollup expressions for the new dimension.
Select to use mathematical operators to define the custom rollup.
Type the name of the existing dimension table column that will store the mathematical operators, or click the edit (...) button to display the Define Custom Member Column dialog box, where you can select an existing column or define a new one.
Select to use a Multidimensional Expressions (MDX) expression to define the custom rollup.
Type the name of the existing dimension table column that will store the MDX expressions, or click the edit (...) button to display the Define Custom Member Column dialog box, where you can select an existing column or define a new one.