When using a multisite structure, you have the option to decide which users will be added to each site. This allows you to control users’ access to your site. For example, if a contributor needs access to an English and French site, but not a German, then you can simply add that user to those two sites rather than all of them.
You can add an existing user to a site from the “Add New User” page of that site. Simply enter the email address or username of the user, then choose a user role from the dropdown menu. The same user can have different roles depending upon the amount of access and control you would like them to have for each site. See the “Difference between WordPress user roles” guide for information on the different user roles.
Once you have added the user to a site, they will receive an email asking them to confirm the invite. If you would like the user to be added to the site without a confirmation email, simply select the “Skip confirmation email” checkbox.
Finally, click the “Add Existing User” button in order to add the existing user to the site.
Author: Anne White