As per the photo, when I use smoove, I can not create a neat slope down from the golf course. I am trying to make it look like the golf course is on a mountain.
You could create a terrain separate from the golf course and then modify it (with Sandbox Tools) as close as possible to the desired shape. Then cross the two lands and delete what you do not need.
To increase your chances of getting help, when you distribute the sketchup file, it’s a good idea to save it in an older version so it can be opened directly by those who have SketchUp Make 2017 or older.
So I’ve moulded a mountain around the golf course and stamped the golf course, althought there appears to be multiple errors. Can you please take a look.
If this it’s what you are looking for, you could use my method, which I wrote to you in the first answer.
I only use Sandbox tools, if you have Artisan, then making the new terrain is much easier.