Only display content that belongs to User in admin/content I have a role called Content Editor and 2 users Chang and Liang with that same role.

They can both add/edit their own content. The role permission is set in such a way that they can only edit own content.

However, when Chang navigates to /admin/content, this user can see all the contents written by all the users.

How to restrict Chang so that he can see only the contents he has written when visiting the /admin/content link?
I created a sandbox-module for that called Content Admin Access
Maybe this is what you are looking for.

With Content Admin Access you can set permissions to show or hide others content in the admin/content overview.
Enabling this module will by default show only your own content in the admin/content overview.