Click on Account Settings
Click on Employees & Services
Select the desired employee
Click on Permissions
to 9. Click on the "Yes" option for the desired parameters
10. To know more about the options "Can view all clients in account" and "Can view clients' contact info (email, phone number, etc.)" click here
If there are two people in charge of your business, you can use the Account Administrator option to allow a second person to have access to all information.
If your business employs secretaries or assistants, you can give them access to other professionals' schedules by using the Can manage schedule of all employees option.