That's the user library.
You should double click the hard drive on go to library/audio/plugins/components. They're all there.
That folder is empty too, at least it was. I placed a new folder named Test in it. This new folder appears in the components folder accessed via the path I described, and the path you describe, leading me to believe they are the same folder.
If I go into System/library/audio, there is no plugins folder, only one called Tunings. there is a components folder lower down but no relevant files appear there.