To do a search for a member, you need to select Members from the drop-down menu. I searched for a member and his name came up in the results.
To search for key words in all topics, you need to select "All Content" from the drop-down menu, then type the words in the text box.
Click on the word "search" and the default setting will appear. Click on that and select what you are looking for from the drop-down menu. Then, type the Name or words you are searching for.