Maybe allow selection of multiple, exclusive search result facet values

[derekenos]

It's not currently possible to select multiple, exclusive facet values (i.e. select and apply facet values using logical OR instead of AND). One complication with heterogeneous search results with respect to applied facet values is that it may become necessary to visually indicate to the user which facet value(s) apply to each result.

As an example of how the current UI doesn't support this, in the following screenshot, if I wanted to select the two Guest Author values Algis Budrys and Anne McCaffrey:

it's not currently possible because as soon as I click on Algis Budrys, a new search will be performed, producing results that do not include Anne McCaffrey as a Guest Author:

An Apply button could make sense somewhere in here.