How to redirect users based on role and content of redirect_to?

The login_redirect hook does seem to be the right hook.

Can you try this :

(Adapted from the Codex )

function redirect_users_by_role( $redirect_to, $request, $user ) {

    if ( isset( $user->roles ) && is_array( $user->roles ) ) {

        if ( in_array( 'staff', $user->roles ) ) {

            if ($admin_url === $request){

                return home_url('/resources');

            } else{

                return $redirect_to;

            }

        }
    } else {

        return home_url('/access-denied');

    }
}


add_filter( 'login_redirect', 'redirect_users_by_role', 10, 3 );