Hi Haser,
I have answered you clearly through Ticket system about the solution to setup the layout like on demo site. The layout (on demo site) you mentioned:
joomdonationdemo.com/edocman/index.php/e...an-layouts/tree-view
It's main layout of Edocman "Categories", at the left hand side, we have module Edocman Categories tree. It's clearly and i believe if you know about Joomla, you should be able to set it up.
If you want me to setup that layout for you on your site, please update the Ticket system with your site url with super admin account. It will save your time
Dam