If a user click on a facet, let's say a term facet, we can add a new filter to the request based on the term facet he clicks on and on the value itself.

For date histograms, we can imagine that the user wants to dive in dates.
If we start with a year interval and if the user click on 1971, we should add a filter on the date field and ask for a month interval facet.

What I would love to have with Kibana is the navigation by facet as I did it here: http://www.pilato.fr/devoxxfr_demo/ (click on Analyse tab and click on a year or on a term facet).