Navigation groups in resource subnavigation

public static function getRecordSubNavigation(Page $page): array
{
    return [
        ...$page->generateNavigationItems([ViewCustomer::class, EditCustomer::class]),
        NavigationGroup::make('Label')
            ->icon('icon here')
            ->items($page->generateNavigationItems([ViewCustomer::class, EditCustomer::class])),
        NavigationGroup::make('Label')
            ->icon('icon here')
            ->items($page->generateNavigationItems([ViewCustomer::class, EditCustomer::class])),
    ];
}