[Plugin: Posts 2 Posts] reciprocal connections

To see connections on both edit screens, set reciprocal to true, but note this is for the UI only, it doesn’t affect connections otherwise.

function my_connection_types() {
    if ( !function_exists( 'p2p_register_connection_type' ) )
        return;

    p2p_register_connection_type( array( 
        'from' => 'movies',
        'to' => 'actors',
        'reciprocal' => true
    ) );
}
add_action( 'init', 'my_connection_types', 100 );