How to specify an environment group for prod and one for previews?

I’m seeing some OLD posts (2+ years old) about separate env groups for preview and prod.

I need to say “Here’s the environment group for previews” and “Here’s the production env group”.

Is this feature still not available? It’s been talked about for like 4 years now? I’m in the middle of switching a project over from Heroku and AWS to render and this is concerning that we can’t do two separate env groups.

I need to keep prod ENV vars separate from preview b/c they are credentials
I need previews to have predictable env vars and not manually set them up for ever PR deployment.

What’s the current (2025) way to do this on Render?

I was hoping we could just say:

fromGroup: prod-env-vars
previewFromGroup: prev-env-vars

but that seems not to exist yet?