Wrodress multisite menu

gistfile1.php

$slot = 1;

function ra_wp_nav_menu_filter( $content, $args ) {
	global $slot;
	$locale = get_locale();
	$registered = get_registered_nav_menus();

	$current = array_slice( $registered, absint( $slot - 1 ), 1 );
	if( empty( $current ) || empty( $current[$args->theme_location] ) ) {
		return $content;
	}

	if( is_main_site() ) {
		set_site_transient('multisite_site_menu_'.$locale, $content);
	} else {
		$content = get_site_transient('multisite_site_menu_'.$locale);
	}

	return $content;
}
add_filter( 'wp_nav_menu_objects', 'ra_wp_nav_menu_filter', 10, 2 );