In this article, I'll walk you through how to perform an Advanced Search.  Sometimes this option isn't immediately noticeable by our users, so I'll provide some screenshots:

Step 1 - enter a search term as you normally would.  I opted to go with example keywords "african american youth" and selected "Organizations" from the drop-down menu to restrict my results to just organizations

Step 2 - Because I limited my search to just organizations, I see immediately the Advanced Search link.  Otherwise, you may have to click on one of the filter links (Organizations | People | Groups | etc..) to limit your search first.  Click on the Advanced Search Link

Step 3 - The Advanced Search panel opens up and you can see more options to limit your search by.

Step 4 - I opted to keep the same keywords and choose to limit my Areas of Focus instead.  Note that you can only restrict by one type of Area of Focus at a time.  As you type, the site will search for the closest match and provide a handy drop-down menu.  Once you're done, click the search button on the right side to resubmit your search.

That should do the trick!

If you have further questions, feel free to post a comment or send an email to support@wiserearth.org.