Multi-fact reports with aggregation by common dimension are helpful to compare common fields across facts, manipulate the data cube, and drill down to examine aggregated data in different areas. Creating a multi-fact report with aggregation by common dimension is similar to creating a basic multi-fact report but includes extra steps for mapping the fields from different facts to common report fields.
You can add an unlimited number of facts to a multi-fact report with aggregation by common dimension, but you can only add fields from dimensions all the reporting facts have in common. In the Common Dimension Example image, Commodity is a dimension common to the Purchase Order and Invoice facts, so a Commodity field can be added to the report. The resulting report can display PO Spend and Invoice Spend broken down by Commodity.