How to filter the inner Nodes with gqlgen

Question

I am using gqlgen to generate boilerplate for graphql queries. How do I generate a resolver for the inner nodes?

For instance, I have a Region schema with [school] array but I also need a filter for the school array. School schema contains classes array which again can be filtered by id. The below query would return all the schools and classes. But as mentioned I also need ability to filter the Schools and Classes in the same query.

type Region {
  id: ID!
  name: String!
  schools: [School!]!
}  
type School {
   id: ID!
   name: String!
   classes: [class!]!
}  

type Query {
  regions(id : ID!): [Region!]!
}