How to split users or teams with projects?

[Veniamin]

I need some help. How to split users or teams with projects? Now every jira software user see all project but I want them to see just one or two ^) 

[Joe Pitt]

You need to redo permissions. 

First, by default JIRA has a horrible permission scheme that violates security best practices by allowing everyone that can logon to do just about everything.

JIRA works by GRANTING access. You can't restrict access. By default, it grants access to the group used to logon (see Global permissions to see the "can use" groups and admin groups).  This is where users are getting the access from.

1. The FIRST thing you need to do to get control is to remove any groups with logon privileges from the permission scheme unless you absolutely want everyone to have that permission.
2. Then I suggest you setup Project Roles for the various functions like, tester, QA, Browse Only, etc.
3. One permission scheme will cover almost all projects. The project admin controls project role membership

This may be a big effort, but it will pay off down the road by making it easy to control access.

Most of the 'old timers' use project roles. It meets the best practice for security and gives complete control to the project lead for access to their project. JIRA comes with many project roles, but you can add more if you have a special need.