Netbeans configuaration

Netbeans configuaration

I used to know this, but I can't seem to be able to reconfigure my new
system to have it behave like before and I'm clueless about what keywords
I have to search for.
Here is the deal:
I used to add some directory at a specific point (I think in the Projet
Configuration) of Netbeans. By doing this, I was able to navigate through
the include directories, there would pop up a small window listing the
files and folders in the currently selected directory branch.
For example, when I added the immediate root directory of a folder named
environment, then I used to type #include "e and the aforementioned window
would pop up.
Does anybody know the answer? I am searchig for it on the www for days
now, but I neither can't seem to remember nor do I know the right keywords
(since I don't know what I'm looking for).