You can hide assets like samples or presets from the community to prevent them from appearing in search results. However, if a re-mixable track contains hidden assets, you will be able to see them when opening it in Studio so that you can make a proper remix. Nevertheless, you won't be able to copy them into a new project. That is a more open approach than making your assets all rights reserved, which force the track to be private and non-re-mixable.