Displaying the variants according to the options

Hello,

I have a shop in which I am selling smartphones cases.
In the product page, I have a collection named “Cases”. In that collection, I have 2 options, “Brand” and “Model”. Then I have variants in which I link the brand and the model (e.g. Apple / iPhone 13 Pro).

On the product page, I have 2 dropdown menus: “Brand” and “Model”. Right now the “Model” dropdown menu displays all the models, no matter the brand the customer is selecting.

I would like the “Model” menu to show only the cases linked to that specific brand. How can I do that WITHOUT using a 3rd-party app?

Is it something I should change in the code itself or in the product page?

I am using Brooklyn theme.

Thank you :slightly_smiling_face:

Anyone?