Hi, Doddy Yulihartanto,
your question is not quite clear. In principle you should be logged into your Mac as a user, say "Arjuna". open a new finder-window. It should show you a folder of the user "Arjuna"; probably the Desktop, or the homedirectory. From the menu "Finder->Preferences-> SideBar, you can select which folders are shown, eg. "Music". This is the Music-folder of user "Arjuna".
As user "Arjuna" you cannot see the folders of user "Bjanu" or so ...
Tell me if this helps, or give more details to your question.
Cheers, thomas