function plt_hide_jetpack_menus() {
//Hide the "Jetpack" menu.
remove_menu_page('jetpack');
//Hide the "Jetpack → Jetpack" menu.
remove_submenu_page('jetpack', 'jetpack');
//Hide the "Jetpack → My Jetpack" menu.
remove_submenu_page('jetpack', 'my-jetpack');
}
add_action('admin_menu', 'plt_hide_jetpack_menus', 1001);