As far as I can tell the main search bar for lists only searches public lists. I have quite a lot of private lists, and it can take a lot of scrolling and clicking to get to the ones later in the alphabet on my user lists page. The "Tip: You can create new lists from here" message kinda looks like a search bar with the way it's colored but it's not lol. I'd love to be able to just start typing the name of a list and have it come up easily