Steam Co Op

Hello, I have a question about PUN in general and Steam regarding CCU and pricing.

Say I made a game that has a max player limit of 10 players max per 'host'.

Does the 20 CCU Limit apply to 2 'worlds' being played and it is now capped at 20 CCU? Or is each host their own 20 CCU?

Example game: A party style game where friend play together. 9 friends on one host and another host , who has 9 friends with them totally 20 total players playing the game on separate host who are not related or in the same session.

A Co-op game bascially.

Does this apply the 20 CCU Limit or is it 20 max players per host since the host is the 'server'.