How can i make a landscape passtrough more accurate than with the visibility tool

See picture, I am trying to make an entrance to a bunker (this wil be mutiple).
The bunkers are hidden in the landscape and i want to make some parts enterable
I tried this with the visibillty tool in the landscape editor but as you can see in th picture this is not accurate even if i use higher resolution for the heightmap import.
How can I accomplish the better result for the entrance?

Thanks in advance
Andre

You can “cut” landscape if size is good, but rather use landscape hole material for things like this
link: Landscape Materials | Unreal Engine Documentation