---> Controller (dir)
------> baseController.php
------> extController.php
------> admin (dir)
---------> user.php
------> user (dir)
---------> user.php

namespace controller;

class baseController
{
    .
    .....
    ....
 }

namespace controller;

class extController extends baseController
{
    .
    .....
    ....
 }

namespace controlleradmin;

class user extends controllerextController
{
    .
    .....
    ....
 }

namespace controlleruser;

class user extends controllerextController
{
    .
    .....
    ....
 }