How to navigate between sites while using the site virtualhost?

Issue

Create a site and add new page to it.
In the site's Configuration > Site Settings > Site Configuration >Site Scope > Site URL. Here add your sites virtualhost, example: www.mysite.com and save the configuration.
Now go to Global > Site Builder > Navigation Menus. Here create a navigation-menu, example: nav1.
In nav1 click New > URL. To Name* add as site name MySite, to URL* add as the url http://www.mysite.com and click add.
Go to your DXP site. In the Navigation Menu portlet > Configuration > Choose Menu select nav1 save the configuration.
Click the site name.

Result: The admin user is navigated to MySite with the URL > http://www.mysite.com