Sitelinks (that's the name) is something that Google does by itself when it thinks it is relevant and makes the life of the user easier.
They study the structure of the site and if the links are of quality and/or relevant to the query they will be shown
These links may help you
https://support.google.com/webmasters/answer/47334?hl=en (hopefully, this will be in English. It doesn't matter what I do, I see it in my own language)