apply_filters( 'site_search_columns', string[] $search_columns, string $search, WP_Site_Query $query )

621			 * @since 4.6.0622			 *623			 * @param string[]      $search_columns Array of column names to be searched.624			 * @param string        $search         Text being searched.625			 * @param WP_Site_Query $query          The current WP_Site_Query instance.626			 */627			$search_columns = apply_filters( 'site_search_columns', $search_columns, $this->query_vars['search'], $this );628 629			$this->sql_clauses['where']['search'] = $this->get_search_sql( $this->query_vars['search'], $search_columns );630		}631 632		$date_query = $this->query_vars['date_query'];633		if ( ! empty( $date_query ) && is_array( $date_query ) ) {