(The following function is only available in Dimensions Analytics). 

Similar to the boolean NOT operator that can be used in a keyword search to exclude certain keywords and phrases, it is also possible to exclude specific entities, such as research organizations, categories or countries, found in the filter panel on the left. This allows for more nuanced queries which may help you to pull exactly the data you need for your analysis.

Simply select one or more entities in a filter and then click on "Exclude" at the bottom of the page.

FAQ

I can build a query like NOT(ResearchOrg A OR ResearchOrg B) - but is it also possible to build queries like NOT (ResearchOrg A AND ResearchOrg B)?

No, this is not supported.

The Exclude button is greyed out - why?

Exclude can only be applied to existing queries. You need to search for something first, e.g. a keyword or an entity from one of the filters.

Is is possible to select entities across different filter types and exclude them?

No, you can only select entities from one filter type .