Any Instructions about how to use Mesh Merge Culling Volume?

Anyone know how to use Mesh Merge Culling Volume? I didn’t found any useful information about this volume. I try to put it in my level, and it doesn’t seem to work.
When I use the freezerendering, I can still see that some cubes are occluded not treat them as a whole.
![Snipaste_2022-05-07_09-05-23|690x416]


(upload://w3F069Z0Tqey1NVEYqVmOBdC2Hn.jpeg)

Thanks in advance.