There isn't a specific 'Folders Only' option but you can search for zero size files, which is pretty good alternative:
- Switch the size to 'Byte'
- Set the Less than edit box to 1
- Enter the folder name in the 'File name:' box.
FileLocator Pro has specific 'Folders Only' functionality. For more information please see this article:
How To Search For Folders - FileLocator Pro