That's not what you asked ... and that jpeg that you posted does not show a screensaver. It shows a background image (wallpaper) 😎
But, yes, I have seen the screensaver that you are actually wanting. There's a youtube or two of that animation. But, no indication that video can be used directly as a screensaver. I wouldn't know how to use it as such. Maybe you do...
I did some quick searches, finding the high-res background images, but nothing about the screensaver, other than those youtube videos.
I wonder if the MacPro comes with that screensaver - or if connecting the XDR enables that screensaver as part of the default setup when you actually have an XDR display connected?
Or, maybe the background image itself is animated, similar to other Apple stock backgrounds that adapt to the time of day