Distinguishing HASONEVALUE from ISINSCOPE
This article describes the differences between HASONEVALUE and ISINSCOPE, which are two useful DAX functions to control the filters and the grouping that are active in a report.
HASONEVALUE and ISINSCOPE are two DAX functions that are mostly used by developers to check the current level of a hierarchy. It is very common to see code snippets like the following, to show the value only at the Year level and below: