JP CE 404 Helper for YOOtheme Pro is specifically created to be a helper on these templates. The JP CE 404 Helper searches (from error URL) similar pages on your sites (or shows most popular if no results).
This plugin is a "Custom Element" and it's very easy to add it to the 404 page. To create a 404 page, open the YOOtheme builder and click on templates. At the bottom of the left side panel you have this text "Visit the 404 error page to create a template for it and return to the Home page.". Click on the "404 error page" link and start designing your template. Design this page as you like and add the JP CE 404 Helper at the bottom (or where it best fits your design). You can see a demo here: https://joomlaproffs.se/uppgradera-webb
This plugin works with YOOtheme Pro Builder ONLY.