Your User access level may be restricted from performing this function. Please see User Roles for more information
When a license has Site Segregation enable, users with the appropriate permissions can grant access to a Facility's data to other users.
See also the Managing the facilities a user can access page that details how you can see and manage all of the facilities available to a particular user.
Go to Facilities > ACTIVE FACILITY and click on the Facility you would like to manage access to:
Change to the USER MANAGEMENT tab:
Click on the green + symbol next to the user to grant them access to that Facility:
Once you have clicked on the + symbol, click on the to confirm or the to go back: