As someone who worked at both Brain and DeepMind: their cultures were very different. Brain was bottom-up, open-field research whatever you want/care for. DeepMind was much more narrowly focused and massively more top-down.

What’s the name of the other group?

Deepmind. I'd say it's actually more reputable than Google Brain.

Deepmind

DeepMind.

A decent amount of people seem to be unhappy/leaving deep-mind due to the forced focus on AI and lack of freedom currently though. Therefore the point above still stands.