There is no filter available in default opencart category listing in admin section, so that you are facing issue to find the specific category from the big category list, and have to do find by paginating the category list one by one. It's not a good practice and more time taking process. This extension will help you to find any of the categories from the list at once in a second. Very helpful extension for all the middle and big level of the websites. Addon it in your admin.