Multiple users list for each customer

we need to keep multiple list of users that are using our app.
The problem is our software is used by multiple companies that has their own users list (not customers but employees).
Is it possible to handle not one large list of users but multiple lists? So we could describe which list are for which customer?
And additionaly can we handle permissions described by administrators of each customer administrator?
Thanks for response in advance! :slight_smile: