Please use the below regular expression which will allow you to retain a folder while excluding its subfolders and files.
Regex: <name of folder>/.*$
Root = svn://gargantua/DEV/trunk/3rdParties/java
Excluded = binaries/.*$
Here, any sub-folder that comes after binaries will be excluded while retaining the content of binaries.
In the log, with the DETAIL level, we can see all the different folders that have been ignored.