PATH Returns a delimited text string with the identifiers of all the parents of the current identifier, starting with the oldest and continuing until current.
Syntax
PATH(ID_columnName, parent_columnName)
Parameters
ID_columnName – The name of an existing column containing the unique identifier for rows in the table. This cannot be an expression. The data type of the value in ID_columnName must be text or integer, and must also be the same data type as the column referenced in parent_columnName.
Parent_columnName – The name of an existing column containing the unique identifier for the parent of the current row. This cannot be an expression. The data type of the value in parent_columnName data type must be text or integer, and must be the same data type as the value in ID_columnName.
Return Value
A delimited text string containing the identifiers of all the parents to the current identifier.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference