How to use dgraph to perform subqueries

[luke]

Thanks a lot.With your help I try my query like this

{
  find_user(func: eq(user_name, "t.t")) @cascade {
    user_name
    ~visit_user_name @filter(eq(visit_time, "2023-01-01")) {
      url_name
      es_id
      belong {
        app_name
        app_host
      }
    }
  }
}