You can add Exceptions which modifies the synchronization method for either files or directories.
For directories, be sure to add a / (forward slash) at the end of the directory name.
For files, include the entire path beginning with a / (forward slash) and ending with the name of the file.
All sub-directories of a directory will be affected. Example: Choosing to "Skip" the directory /MUSIC/ will also skip /Music/MyBand/Ice.mp3