Question posted in 
I want to achieve this when a site is searched for on Google (sub links below description).
Are these Google Sitelinks?
From what I’ve seen when researching into this, Sitelinks are larger and sit side-by-side, as shown in the image in this question.
If these aren’t Sitelinks, can they be defined and how would this be done?
2
Answers
Yes these are sitelinks, the large and big sitelinks mainly they appear for the homepage or any other pages you have with a high page rank.
The little links that appears beside each other are also sitelinks for page that have less page rank or less content with poor HTML structure.
You can’t control which links to appear on Google, many factors affect them like HTML structure, page rank, content, CTR and search query.
You can only remove them from Google webmaster tools by demoting a certain link from a certain page you have.
These are one-line sitelinks, introduced in 2009-04.
They are similar to the “full two-column” sitelinks, but one-line sitelinks can appear for every result, not only the first one.