What are Google Sitelinks?
As you’ll see from the image, the Tweed Valley Website has 6 extra pages listed below the homepage link. Not every website has this (some may have 2 or 4, many have none).
The benefit is visitors can can gain a better understanding of what your site is about before clicking, and they can take a short-cut to a page that interests them, rather than getting to the home page and then having to use the menu.
How do you achieve that? Google don’t let on.
Some factors though, undoubtedly, are: easily searchable, structured navigation; strong organic search traffic; high click through rates from search results page; and unique page titles and meta descriptions on internal pages.
Generally speaking then popular internal pages appear as sitelinks.