How to use responsive-file manager inside of codeigniter application folder

Question

I use responsive file manager in my project, now i can access that from assets folder using the link is below,

<li class="m-menu__item" aria-haspopup="true">
   <a href="<?php echo base_url(); ?>assets/responsive_filemanager/filemanager/dialog.php?type=2" class="m-menu__link filemanager_iframe">
    <span class="m-menu__item-here"></span>
    <i class="m-menu__link-icon la la-file"></i>
    <span class="m-menu__link-text">File Manager</span>
   </a>
</li>

above link wise, i have to link dialog.php with type query string, with this i can access file manager now, but my problem is i can't able to access any code igniter database functions and sessions out side of assets folder, thats why i am trying to access responsive file manager from anywhere of application folder,

Thank you..