Understanding User Permissions and PII Restrictions in Enterprise Features

I'd like to understand more on user permissions, and how we can restrict certain PII. For example, is it possible for some viewers to only see published insights? OR certain feeds? And if this was a restriction would that limit what magic search and summaries were produced for them? I might be diving into Enterprise features here, and i'm ok with that, I just couldn't find any help that wasn't too technical on user groups. Thanks in advance