This would be very handy when making a visualization involving tunnels, cellars, caves etc. Currently I'm just sculpting the landscape around the parts that need to be underground, and this is very awkward solution..
Hi ,
Right now, aside from the terrain sculpting tools, there isn't a way to cut holes in the landscape. If you think this would be a useful feature, I recommend submitting a request for it on our Public Roadmap here, as this is the best place for these kinds of feature requests.
Best,
Raghib