An important update has been made to the Google Custom Search Engine personal search engine. Now, when adding a site to be indexed by your search engine, you can include in the search pages that are linked to the added site. So if you used Custom Search Engine to search one site, then now you have the opportunity to convert it into a single ecosystem of pages relevant to your site.
All that is required of you is to select the option “dynamically extract links from this page and add them to the search area”. There are also three additional options for this parameter: include either all pages, or subdomains, or entire sites that your site links to.