WordPress Search in taxonomy

in_taxonomy.php

<?php

add_filter('posts_search', function ($search, &$wp_query) {
  global $wpdb;
  if (empty($search) || is_admin()) {
    return $search; // skip processing - no search term in query
  }
   
	$s = get_query_var('s');

	// SEARCH IN TAXONOMY
	$term_query = "OR ("
					. "{$wpdb->posts}.ID IN ("
					. "SELECT object_id as ID "
					. "FROM {$wpdb->terms} "
					. "JOIN {$wpdb->term_relationships} ON {$wpdb->term_relationships}.term_taxonomy_id = {$wpdb->terms}.term_id "
					. "JOIN {$wpdb->term_taxonomy} USING (term_id) " // In specific taxonomy
					. "WHERE {$wpdb->terms}.name LIKE '%{$s}%' "
					. "AND {$wpdb->term_taxonomy}.taxonomy = 'post_tag')" // In specific taxonomy
					. ")";

	$search .= " AND ({$wpdb->posts}.post_title <> '') "; // exclude empty titles
	$search .= " AND ({$wpdb->posts}.post_status = 'publish') ";
	return $search . $term_query;
 
}, 500, 2);