How do I hide a folder?
First you need to realize, that hiding a folder with CallbackFilter doesn't remove it's contents from the disk. The data remains available if the user boots in safe mode or other OS or just moves the drive to other computer.
If this is ok for you, you can set rules or use callbacks to (a) hide the folder during enumeration by skipping it's name (if you use callbacks) and (b) prevent enumeration of contents of this folder. Step B is necessary to don't let the OS directly access folder contents (eg. if the user knows the name of the file inside the folder being hidden).