Is it possible to create a DateRange Aggregation where, instead of specifying a
field, I can specify a script which will produce a Date from a number of source fields? In my case, there's a "good, better, best" set of dates in 3 different fields (all optional expect the "good") in my documents that I'd like to choose from dynamically as each hit is produced. That is, if the "best" is populated, I'll return that one and so on.
My web searches so far haven't produced any results so I'm doubtful it's possible but thought I'd raise the use case and see.