Marco Russo and Alberto Ferrari looks at calculation groups:
Calculation groups are often used to display options in a report to change the calculation of existing measures by selecting items on a slicer. However, only a single calculation item can be executed for a measure reference, which could make the semantic model harder to use when the user selects two or more items in a calculation group.
Two new calculation group properties, multipleOrEmptySelectionExpression and noSelectionExpression, provide a way to control the calculation in these conditions that, so far, ignored the presence of the calculation group, thus executing the measures without applying any transformation. This article shows how to use these features and provides guidance on using the feature in preview: despite not having a user interface to manage these new properties, the TMDL view in Power BI Desktop and external tools like Tabular Editor already allow you to create and publish a semantic model that uses these new properties.
Read on to see how these properties work.