In Solaris, to create and use a Sample Filter, create a RenderMan Render Properties LOP Node. This has a lot of the familiar parts of a ROP but re-arranged.
Look under Image Output and then Filters. Only built-in options are available so there is a dropdown menu to select your options.
Here's an example of options for built-in Display Filters
Note the tabs 1 through 5 for additional filters executed in order.