When you're on the books journal page: 1. Click on the little globe on the far right of the "booksellers" button 2. On the following page you've the global overview for the book with a line saying "Wishes for this book: click here" - and you do!
Or: use the "search" item under the "books & people" tab, select the "wishlist" option, and fill in the fields - I generally use the basic title (leaving off any leading "a" or "the") and the author's last name. [The global-overview method that Bluemchenblatt described will take you to the same wishlist-search-page, so it should work out either way!]
Side note, for the benefit of newbies who may be reading about wishlists for the first time: you are NOT obligated in any way to offer your books to people who are wishing for them. If you want to offer to send the book, whether in trade for another book or for postage, or for nothing at all, it's entirely up to you. Do take the time to check the profile page of anyone you want to contact; they may have stated that they prefer not to be contacted, and if so, respect their wishes.
I also find it helpful to include a time limit, such as "I'd be glad to send you [this title] from your wishlist; if you'd like it, please send me your address before mm/dd/yy." That way, if you don't hear from them by that time, you can release the book elsewhere in good conscience.