@Live000, If you are only having grass texture on your landscape, you can set your landscape paint brush to “Pattern” then load a mask like those circles and paint with it. If you have grass meshes on your landscape and you have used landscape grass tool to distribute them, and in case your landscape isn’t big, you can create a top down mask something like what you have posted, with everything being black and circles being white, then subtract the mask from what you’re plugging to the grass node inside your landscape material.
But if you’re doing this for ArchViz then what Deathrey mentioned seems to be the better approach.