Create a lookup field that searchs only the selected dropdown field

Question

In my product register page, I want to create a search field next to the dropdown list, that will search only the object selected in dropdown. An example: In my drop down I have Audi, Dodge, Mercedes and Seat; You select Audi from the dropdown; I want to create a search field that will only search the audi models. Any ideia how can I do it? Thanks!

Answer 1

Lookup filters based on a picklist on the same record will only work if you save the selected picklist value first. I assume that is not an option for you.

I see these options for you, based on whether or not you need the models in a separate object:

1) create another picklist with the models and use dependent picklists to capture the allowed brand-model combinations (this won't work if the models are in another object)

2) create a VisualForce page that dynamically loads a picklist with the models