Conditional filtering for dropdown boxes

seeking advice or demo code on the process of creating conditional filtering two drop down boxes, the first box e.g. brand and the second e.g model. i have created two database tables, brands and models. one brand has many models, so i have created a reference field to show this, in my brands table. examples i have seen online dont show how to use reference fields and they are not a possible connection for the data sets on the page.
so far i can get the brands to show and the models to show, however i cant seem to get it working with the filtering in place. does anyone happen to know how to get this to work? without having to compromise on data integrity.
I have code in place to handle the event changes, and used the wixData.filter() its just the actual filtering and the display of models in the second drop down after a brand is selected which is driving me insane.
thanks in advance.

work around, using the cascasing form method… with ALOT of changing code to actually make it work.