Field Parameter - Hierarchy

Hi joshua1990 I had the same issue and I found something that worked!!

I set up two separate field parameter tables which have a one to one relationship with each other on an additional column (Value4 in my model) in the “top layer” field parameter table. You just need to edit the top layer field parameter table DAX slightly. I made a simple data model with a master data table and 3 dimensional tables with 2 layers of hierarchy (Region -> Country, Vertical -> Industry, Product Group -> Detailed Product)
Here is the result...

Top level:

Ability to drill down (expanded Hierarchy, but all the other drill down options work):

Sample model (Requires additional “Value 4” column):

Table definition for "Parameter" table - note I generated this table with the Field Parameter feature, then edited the definition slightly to add the second hierarchy layer name:

Then the parameter fields from each parameter table go into your visual. 

I’ve attached the sample pbix: Field Parameter within Field Parameter.pbix Let me know if this works for you!
14/06/23 - Link has now been updated, seems it has expired, should be working again.