In that type of scenario you would have to use guest access -- basically create a special room and only use it for the users that you don't want to have full access as normal users in the group.
Take a look at the knowledge base article Guest access for more information.
Badges are a great way to show off community activity, whether you’re a newbie or a Champion.Learn more
...attest to the experience of an urgent approval that gets lost in the boss’s inbox and requires that special “Please Approve” email or text message. In an age where we have distributed teams...
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