Codeigniter 3 + HMVC (sub-direcotry in modules)

I use HMVC wiredesignz third party to use modular structure for Codeigniter.

I there a way to create a subfolder in the modules directory ?

I want something :

Code:

modules
   module1
      controllers
          Module1.php
      ...
   admin
      module2
          controllers
              Module2.php
           ...    
      module3
          controllers
              Module3.php
           ...

Of course I've tried to call with :

Code:

base_url('admin/module2/index');

I've got a 404 error. Is this possible ?

Thanks