WordPress permalink for custom post type based on post meta

custom-permalink-from-meta.php

add_filter( 'post_type_link', 'my_post_type_link', 10, 3);
function my_post_type_link($permalink, $post, $leavename) {

	if  ($post->post_type == 'my-post-type') {
		$meta = get_post_meta($post->ID, '_my-post-meta', true);
		if (isset($meta) && !empty($meta)) 
			$permalink = home_url( "my-friendly-url/" . $meta . "/" . $post->post_name . "/");
	}

	return $permalink;

}

add_filter( 'rewrite_rules_array', 'my_rewrite_rules_array');
function my_rewrite_rules_array($rules) {

	$rules = array('my-friendly-url/([^/]*)/([^/]*)/?$' => 'index.php?post_type=my-post-type&name=$matches[2]&meta=$matches[1]') + $rules;
	return $rules;
}