Your filter matches everything and won't filter anything out.
You have to tell Opus which sub-folders to exclude.
There's an example in this thread (the third screenshot):
resource.dopus.com/viewtopic.php ... der+clause
That excludes anything below subfolders called "old" (as well as requiring files to be called names like 01234.png, but that detail isn't important for what you want to do).
Another example in this thread (first screenshot):
resource.dopus.com/viewtopic.php ... der+clause
That matches all *.jpg files but doesn't look below directories with the Hidden attribute set.