How does the ISINSCOPE function (DAX) work?

ISINSCOPE function (DAX) returns true when the given column is the level within a level hierarchy.

ISINSCOPE Formula Syntax

ISINSCOPE (<columnName>)

How do you use the ISINSCOPE function?

It returns TRUE if the column is included in the filter context, and it is a grouping column in the result set for the current row.

Considerations when using the ISINSCOPE function

When ISINSCOPE returns TRUE, then also HASONEVALUE returns TRUE.

Formula examples using the ISINSCOPE function

DEFINE
MEASURE FactInternetSales[% of Parent] =
  SWITCH (TRUE(),
    ISINSCOPE(DimProduct[Subcategory]),
      DIVIDE(
        SUM(FactInternetSales[Sales Amount]),
        CALCULATE(
          SUM(FactInternetSales[Sales Amount]),
          ALLSELECTED(DimProduct[Subcategory]))
      ),
    ISINSCOPE(DimProduct[Category]),
      DIVIDE(
        SUM(FactInternetSales[Sales Amount]), 
        CALCULATE(
          SUM(FactInternetSales[Sales Amount]),
          ALLSELECTED(DimProduct[Category]))
      ),
    1
  ) * 100
EVALUATE
  SUMMARIZECOLUMNS
  (
    ROLLUPADDISSUBTOTAL
    (
      DimProduct[Category], "Category Subtotal",
      DimProduct[Subcategory], "Subcategory Subtotal"
    ),
    TREATAS(
      {"Bike Racks", "Bike Stands", "Mountain Bikes", "Road Bikes", "Touring Bikes"},
      DimProduct[Subcategory]),
    "Sales", SUM(FactInternetSales[Sales Amount]),
    "% of Parent", [% of Parent]
  )
  ORDER BY
    [Category Subtotal] DESC, [Category],
    [Subcategory Subtotal] DESC, [Subcategory]