|A very long overdue update and requested feature since a very very long time ago, but finally got my lasy ass to fix it.
You can now search your own book list ( or others )
To be able to serach your own list go to your own profile page, you will find a new link saying "Search User Books" on the right side menu, click it to get to the serach page for your books.
The serach page is basically the same as advanced search and you can search your items by name, content and the like.
Example of a random user with a list: https://www.doujinshi.org/user/deiv/search/?order=title&flow=ASC&age=N&Q=s&age=N&page=1
Please repot any errors you may find with this function, it's still pretty new.