In the Summon OBI analytics, you can create a Zero Title Searches report, which includes how many times the search was conducted as well as the "Search Origin." The search origin provides the information on the cause of the search coming up with zero results that can either be due to a "search" or "facet."

Currently, we can't see precisely what facets the user had selected while searching that provided zero results. We believe that including details on which facets were present during the failed search would be extremely beneficial.