Time Capsule how to setup secure shares?

So, i've searched quite a bit but haven't found the answer to this.

Have a 1TB time capsule, currently using it for storage and now to backup one of our macs, will add another soon.

Question is. How can one, if it is possible switch the time capsule to only share/show data that one has put on the time capsule and NOT the information/files that others have put on the time capsule?

I just don't want people to possibly login to the time capsule with the TC password, and possible delete anything.

Is there a way to do this while preserving the data which is on the time capsule? Ultimately, I'd really like to have a public folder where people can share data, AND individual private folders which are only targetable to the actual user and they have to login to that "share" with their username and password.

 

so

so, what is the setting for "accounts and passwords"?