Have you installed them? Are they Daz store assets? Renderosity? Renderotica? Either way, you aren't going to find them in the parameters pane.
If they're Daz store assets, then you can either find them in the Smart Content Pane (make sure there's nothing else selected in the scene) > Figures. You can also find them in your Content Library Pane, and that's where you'll also find the other two. So for a figure, it'd look something like this: Content Library > My Daz 3D Library > People > Genesis # (by default, it seems as if 8.1 figures are also put in the Genesis 8 folders.) > Find either the character name or the vendor name.