Within the house you live in, people only have to mention your first name and everybody in the house (probably) knows which human they're referring to.

Your scope is "household".

Or maybe all your neighbours also know you, and there's only one person in your nearby neighbourhood with your first name, so again just mentioning your name identifies which human. Your scope would be "neighbourhood".

Maybe on your street, there's three people all with the same first name as you, and everybody knows everybody else. In this case, just mentioning your name on the street doesn't uniquely identify you.

It does in your house -- that still works, but not on the whole street.

Some famous pop stars only use their first name. Mention Beyoncé, and everybody knows who you're talking about. Her scope is global.

If your first name also happens to be Beyoncé, and someone in your family mentions that name, it's clear they're talking about you and not the pop star.

So scope depends on context.

You can have a Beyoncé with global scope, and at the same time a Beyoncé with local scope. In fact you can have lots of Beyoncé's with local scope. It all works because of scoping and context.