I'm not sure from your post whether you want to filter out the ckbk books or recipes. But both are easy fixes. Firstly, if you want to exclude the recipes, you have two options. If you want to exclude them in just one search, tick/check the Exclude Bookmark box then tick/check the ckbk bookmark in Books. Now no ckbk recipes or books appear in your searches. If you want to exclude the ckbk recipes for more than one search, go to your Account page (accessed from the drop-down menu under your username at top right, or under the menu on a phone). Then change the Search Setting toggle for 'Include ckbk recipes in Online Recipes?' to No. Now ckbk recipes won't ever appear in your search results, of the Library or your Bookshelf. You can switch it back on any time.
If you want to exclude the ckbk books from a search of books on your Bookshelf, again apply the Exclude bookmark filter. in books Or if you want to exclude them permanently, go to your Bookmarks page, accessed from the menu under My Bookshelf, select Books, then 'Remnove all from Bookshelf' will take all the ckbk books out of your Bookshelf. Again, you can reverse it if you decide you want them back.