This MS Documentation page shows how to create a cascading lookup for OPTION SETS. This section on that same page shows one very very basic example of how to do this with lookup fields. However, the particular API call in that example fillLookupFromSearch() looks like it is probably just searching the display text. That's probably not going to meet most developers' requirements.
In my team's case, we need to filter a list of COUNTIES based on the STATE lookup. So we'd need to filter on another field of the County record.
I have so far been unable to find reference documentation for the Marketing Javascript API or the fillLookupFromSearch() function in particular to see if there's a way to achieve this. Is there just no API reference available yet?
