If you are logged in as the AMG administrator and can not see an employee, make sure all the fields for the filters presented to you on the screen you are trying to find the employee are set to "Any". Click the Filter button to check the settings. If you still can not see the employee, the employee was likely deleted or never entered in.
If you are logged in as another user, follow the same filter preference instructed for admin, set all the fields for filtering to "Any." If you still can not see the employee, contact your administrator to check your user configuration from Tools - Users to make sure your user has access to see the group, division, and headquarters the employee belongs to.