Problems with creating subfolders in CodeIgniter 3 HMVC

I have a project that contains several subfolders, such as:

1. client (folder name)
    auth (sub folder )
   

                        login(sub sub folder)
                           model+view+controller

                        signup(sub sub folder )
                           model+view+controller

1. admin(folder name)
   

1. • signin(sub folder) 
         model+view+controller
     

I set up my routes like this:

Code:

$route['default_controller'] = "admin/signin/signin";
$route['admin/signin'] = "admin/signin/signin/index";
$route['admin/(:any)'] = "admin/signin/signin/$1";
$route['client/auth'] = "auth/signin/signin";
$route['client/auth'] = "client/auth/signin/signin";
$route['client/auth/(.*)'] = "client/auth/signin/signin/$1";

These routes are not working, which shows CodeIgniter 404 error page.  I have also attached an image of my file structure.           please help to solve this issue.