The goal is to list only the history of hosts in CRITICAL hard state. I do not interested if soft states, only in the hard ones. Icingaweb make the search through the following URL:
As you can see, it shows state changes to CRITICAL, but also shows soft states, when the filter is specifying Host State Type=hard and Host Hard State = 1.
thank you very much for your useful response. Obviously, I was misunderstanding something
In order to target historical events, is needed to prepend the search form with the word Event in the text box and wait to the completion (cool functionality), as this screenshot shows: