Marco Russo discusses ratio-to-parent measures, which use DAX hierarchies, in this short video. You will see how to create such a calculation and how to use it in a Pivot Table (00:30). DAX does not have an internal mechanism for hierarchy navigation, so you need to write the appropriate DAX code in order to obtain the desired results. This technique is available as an Excel feature of the PivotTable, but it requires creating the same calculation in every PivotTable. By creating the measure in the data model itself the calculation becomes available to all pivot tables.

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