Marco Russo and Alberto Ferrari are working for The Man:
The security model in Tabular used by Power BI can filter rows of a table based on a DAX expression. When security is applied to a hierarchical structure, every hierarchy level is represented by a different column in the table. This structure can make it challenging to define a dynamic security filter based on the name of a node in the hierarchy, because the DAX expression must filter the column corresponding to the hierarchical level in which that node exists. If the security needs to be maintained dynamically in a configuration table, the resulting code may end up being extremely complex and hard to maintain, as well as create possible performance issues.
Without describing the complexity of solutions based on a filter applied directly to the appropriate hierarchy level, we want to describe a solution that minimizes the effort required in maintaining a configuration table for the dynamic security rules, while also providing good performance at execution time by minimizing the processing overhead required to apply the dynamic security.
Click through for the scenario and how you can implement this kind of security model in Power BI.