Filter a repeater by another collection

Hi, I’ve been stuck on this for weeks and I’m so confused.

I have a repeater displaying items from a collection titled “Characters”, within a dynamic page. The page is specific to one item within a collection titled “Projects”. I want the repeater to only display items from “Characters” that are specific to that “Projects” item.

I have tried using a reference field in the “Characters” collection, connecting it to the “Projects” collection, only to find out that Wix doesn’t allow you to filter by reference fields.

The solution would involve the system automatically retrieving the required information from the dynamic page in which it is embedded, as this is for a commercial website, so I couldn’t manually input IDs or names each time.

I would be so greatful for any help, as I have no clue now. This is my first time using Wix, so I have no experience.