What DAX function should you use to refer to the current context of a measure in a calculation group?

The function that should be used to refer to the current context of a measure in a calculation group is SELECTEDMEASURE. This function is specifically designed for use within calculation groups in Power BI, allowing the user to dynamically reference the measure that is currently being evaluated in the report context.

Using SELECTEDMEASURE enables the evaluation of different measures based on the filters and slicers applied in the report. This is particularly useful in scenarios where a calculation group is applied to a variety of measures, and you want to create a universal calculation that adapts to the specific measure that is currently being assessed.

The other functions, while powerful in their own contexts, do not serve this particular purpose. SELECTEDVALUE is used to retrieve a single value from a column or table, typically useful for scenarios involving slicers or when you expect only one value to be selected. CALCULATE modifies the context of calculations but does not directly reference the current measure in the same way as SELECTEDMEASURE. SUM is an aggregation function that adds up values in a column, but it does not reference the measure context at all.