How to map different fields?

Hello everyone

I’m trying to build a vehicle app.
I’m uploading some data to the database and I’m trying to map (match) some fields.

I have already uploaded all Makes (Data Type), Models (Data Type), and Generation (Data Type). Now I’m trying to upload Series (Data Type)

I want to reference the Series (which is Cabriole or Coupe or Sedan sometimes it refers as body type) to the Generation. But Bubble cant find which Generation.
Because for each Model, there is at least one Generation.

I thought that Bubble does mapping (matching) based on Model. I realized that it doesn’t.
How can I “force” Bubble to look first in the Model and then based on that Model to match the Generation?

Thanks in advance.
Fabian