hello,
in your CPT people, you save the role in a post_meta ?
you can filter in the wp_query like this :
$args = array(
'post_type' => 'people', // your custom post type
'meta_key' => 'the_role', // the key of post_meta
'meta_value' => 'authors', // for exemple
'meta_compare' => '=',
'relationship' => array( // YOUR RELATIONSHIP INFORMATION
'id' => 'posts_to_pages',
'from' => get_the_ID(), // You can pass object ID or full object
),
'nopaging' => true,
);
$query = new WP_Query( $args );
I hope this helps.