CodeIgniter controller in subfolder

I have a controller in a subfolder. CodeIgniter is giving a 404 page not found.

The controller works fine in the root controller folder. The controller also works fine in the 1st level subfolder. The controller breaks in the 2nd level subfolder.

Why would CodeIgniter not want you to user multiple subfolders?

Example:

Works: controllers/pages/HomeController.php

Broken: controllers/pages/users/HomeController.php

My Routes are like this:

Works: $route['default_controller'] = "pages/HomeController";

Broken: $route['default_controller'] = "pages/users/HomeController";