Before the era of the calculation groups it would have been required to create all these measures separately:
The more base measures and time intelligence variations that are required, the bigger the issue becomes.
Calculation groups create the possibility to define once the calculation logics are needed(calculation items such as Base, YTD, and PY), and then apply them to multiple measures(by using the DAX function SELECTEDMEASURE () in the calculation item).
Calculation groups can be used much like dimension attributes such as customer name or product category in combination with a base measure (NetSales or GrossSales). The selected calculation item will then be applied to the selected measure!
Calculation groups offer the following benefits:
•Model becomes easier to understand and use
•Less initial setup
•Lower risk of inconsistencies and errors
Calculation groups are created by using the Power Bi Desktop external tool Tabular Editor.