PATHLENGTH Returns the number of parents to the specified item in a given PATH result, including self.
Syntax
PATHLENGTH(path)
Parameters
path – A text expression resulting from evaluation of a PATH function.
Return Value
The number of items that are parents to the specified item in a given PATH result, including the specified item.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference