function plt_hide_jetpack_menus() {
//Hide the "Jetpack" menu.
remove_menu_page('jetpack');
//Hide the "Jetpack → Dashboard" menu.
remove_submenu_page('jetpack', 'jetpack#/dashboard');
//Hide the "Jetpack → Settings" menu.
remove_submenu_page('jetpack', 'jetpack#/settings');
}
add_action('admin_menu', 'plt_hide_jetpack_menus', 1000);