Add this method to your detail.php file:
public function admin_menu(&$menu)
{
// Create main menu item
add_admin_menu_place('lang:module:title', 9); // 9 is the placement order of your menu item, it would be after profile
// Create sub-menu
$menu['lang:module:title']['lang:module:submeu1'] = 'admin/add';
$menu['lang:module:title']['lang:module:submeu2'] = 'admin/edit';
}
also set the 'menu'=> false,
at your info()
method.