Filter Woocommerce Related Products By Custom Taxonomy

add_filter( 'woocommerce_related_products_args', 'rare_related_products_by_custom_taxonomy');
function rare_related_products_by_custom_taxonomy( $args ) {

	global $post;

	$tags = wp_get_post_terms( $post->ID, "custom_taxonomy" );
	foreach ( $tags as $tag ) {
			$tags_array[] .= $tag->term_id;
	}

  unset( $args['post__in'] );
  $args['tax_query'] = array(
			array(
				'taxonomy' => 'custom_taxonomy',
				'field'    => 'id',
				'terms'    => $tags_array,
			),
		);
  return $args;
	
}