You can narrow your search by going to the link called, and I will use myself as an example, so in my case:
There are 759 plants in touchofsky's plant list.
Click on that to take you to your Plant List page.
At the top of that page there is a white box, and go to
Show only genus
Click on Show all
A list will come up with all of the types of plants you have, go down the list until you get what you want, in this case, Hemerocallis, click on that and then click on the little green box at the bottom "Update View" and a list of all your daylilies will come up, and only daylilies, listed alphabetically. You can also sort this list by date added. That puts newly added cultivars first.
As, for finding a particular daylily cultivar, the best I have found is to make separate categories. For example, I have categories for miniatures, smalls, seedlings, unregistered, etc., and file them that way, then you can narrow down your search more quickly. You could create whatever categories best suit your collection.