Sitelinks in Wordpress, also called sitemap, can be
created using an SEO plugin such as Yoast plugin.
If you would like to continue showing more information with your ads,
we recommend using Sitelinks, callouts, and structured snippets extensions.”.
Sitelinks- These appear in some results in the SERPs,
where numerous internal links are provided, making it easier for users to navigate directly to the portion of the site that interests them.
If the structure of your site
doesn't allow our algorithms to find good Sitelinks, or we don't think that the Sitelinks for your site are
relevant for the user's query, we won't show them.”.