GraphQL filter nested tags

Hi there,
I would like to only get posts which contains a certain tag.
These tags are a seperate collection and linked to the posts.

This is without populate

This is with populate

So i searched the forum and found out that if i am not using MongoDB (at the moment i am not!) filtering on nested documents is not possible via graphql-query. (am i right?)

The only way to get this to work is to create a custom api/gql endpoint (given i am not ready yet for MongoDB)? (am i still right?)

can anyone push me in the right direction please?
should i start with the following post by Arthur where he tells us how to create a custom API Endpoint ?

Any help is appreciated :slight_smile: