FARAZ said:
I right clicked a folder and chose close this folder to hide the same!
How 2 Locate/Reopen such a folder?
There is no "Close this folder" context menu entry when you right-click
on a folder. There is such an entry when you right-click on the root
node for the message store.
Apparently you had another .pst file opened in Outlook (File -> Open)
and then you chose to close it. Now you'll have to reopen that .pst
file to show its message store and its folders inside of Outlook.