Oh, do you mean only check all services underneath a single host?
If so, you might just leave the host.name in the filter and drop the service.name portion.
Looking for the or syntax for the API for the next idea below, I accidentally found evidence that suggests that only using the host.name in the filter works: Set downtime for all services of one host via API - #2 by metme01454
If that doesn’t work, you could probably filter for all of the service.states:
service.state==0 and 1,2,3…