Apologies if this is possible, but I've not found a way to do it either in documentation, or via trial & error.

We're trying to create locations which have a parent location, but don't seem to be able to do this via Hammer CLI or API. Is this something that is only possible through the WebUI?

I thought that one of the "design principles" (loose phrasing here) of Foreman was that any actions through the WebUI were also possible via the CLI?