Kristyna Hughes makes use of the Tabular Object Model:
Power BI hierarchies are a powerful and easy way to enable end users to dig deeper into their visuals and data. While hierarchies can be a useful resource for self-serve analytics, maintaining hierarchies can be a pain as new levels get added or removed. Thankfully, if you have Power BI premium you can use the XMLA endpoint to add code into existing .NET applications to dynamically add or remove levels from hierarchies as they are created/removed in your application.
Unfortunately, while we can manipulate, add, and delete hierarchies and their levels, visuals already containing the hierarchy will not be automatically adjusted with any new levels/ordinals.
In spite of that limitation, click through to check out what you can do.