The search filters on the left side can be used at any time to go directly to results for a particular entity such as Research Organization, Funder, Source Title, Country, City and many other possibilities (see the “Filters” FAQ section for more details). Each filter presents the top ten entities for that filter, sorted by the number of results for the present search. If the entity you are looking for is not among these first ten, the “more” button at the bottom of the list allows you to type the name of the entity you are looking for. This type-ahead function will then bring up a selection of possible matches for your search, which you can then select from to choose the filter for that entity.
If you would like to see a more complete list of all of the entities in a filter, and not just the top ten, this can be found in the analytical views area under the relevant tab.
(Usable filters in Dimensions are determined by your subscription - not all filters are available in all versions.)