There are different filters on websites in my country and I can not access to several sites.
Can you introduce me some addresses for breaking filters?

Is it filters on someone else's (employer?) computer? If not, what filters are they?

No! If filters exist that screen access to certain web sites, they are placed there by government, organization (school, company, etc.) or parents. In most cases they are placed to protect the computer system used from damage. In some cases they are placed to protect users from unwanted material. In other cases (like yours) they may placed to stifle the free flow of information.

In EVERY case, they are placed by people responsible for maintaining or protecting the system or protecting the users. They have the right to do it. For anyone to help you get around the restrictions placed would be unethical. It can also get you in major trouble.

I think he's referring to ISP level filters here Rickj.

sfem you really haven't got a hope as a lot more counties are now censoring the internet.
So even if we could think of some proxys for you to use you wouldn't be allowed to access them anyway.

Maybe he needs some research for this:
https://www.askmehelpdesk.com/art/make-up-17874.html

Is it filters on someone else's (employer?) computer? If not, what filters are they?

They are governmental filters.

They are governmental filters.
In short you are up a creek without a paddle.
You don't have a hope of getting passed these things.

Unless he wants to dial in long distance and incur large fees and super slow rates.