Sorry for the confusion - was in a rush!
For a site to acheive a sub listing [indexing] of it's pages, as with the Leeds University example, the site:
1. Needs to achieve the top spot in a search result
2. Needs to be relevent to the original search
3. Be an index page be it .htm / html / php or asp contained within a sub folder or subdomain
4. Needs to be considered an "authority" site [see note below]
If another page on the same domain is as relevent to the search result but is not an index page then the page gets listed as an indented result below the original one. This indented result can happen much lower down in the search results whereas for sub indexs the page must hit the number 1 slot.
[quick note about....]
Google ad-sense and ad-words work because they display a link to your site on other sites, thus making your site more relevent and therefore listed higher - as long as people click these links and generate traffic to your site. Which works for both the specific company name and general search terms.
Which leads me to "authority site" status. This is a big one and not easy to answer quickly so I'm just going to deal with a specific organisation name search result. If you get the number 1 slot on a google search then google *may* consider your site to be the authority site because it's THE site for the searched organisation name out of a selection [1000's] of similar or related sites - as a search on Leeds University shows. This will not only place the site in the 1st slot but will allow the sub indexing of other parts of the site to which the home page links.
That's the overview but of course it goes much deeper than that. Even if you hit the top spot you may still be considered *just* the most relevant site rather than The Authority Site. You need to carry out a number of other tasks obtain and hold on to this status.
There are 3 main areas to work on but to save my poor fingers and almost certain brain meltdown here is a handy link.
Authority Site Diagram
I hope this more clearly answers your question