Can I remove or hide the NULL and blank values I see in the data filter on the dashboard in Zendesk Explore?
It is not possible to remove the NULL or blank values from the data filters. The values come from tickets in the system which have no value, in the example above, tickets which have no Ticket Priority.
However, you can exclude these values on the query level. For more information, see the article: How do I exclude blank values from my query?