In D8 I have a custom compound field with subfields that reference taxonomy.
So, essentially, I have one table in the database, containing a column for each subfield.
What I want is to be able to search on a couple fields together, with an exposed filter.
The user has a dropdown of available values, bar-1, bar-2, bar-3 in Column C, where Column B = foo-1, this would narrow their results for related entities (column A).
There would be several of these dropdown, each one limited by a specific value in Column A (Foo-2, Foo-3, etc.)