Hello,

Unfortunately, the global settings are applied to both from a backend and frontend, so you could possibly, change the global settings before creating an appointment from the backend, and then change it back to original settings once you have the appointment created from the backend.

In the services you don't want to be shown on the front-end, you can disable "Show service on site", so they can only be booked from the back-end.

In Settings/Roles/Admin, enable "Allow admin to book appointment at any time", so you're able to book these appointments outside of employee's work hours.

Another option would be to add a new employee, which will cover these services. The custom work hours for that employee could be from 00 - 24h, so they "work" all day. To prevent double bookings (if this is in fact one employee in real life, that will cover all services), you need to configure Google Calendar and link both employees to the same calendar, so when one service is booked, the other services are blocked during those times.

Please reach out to us if you have any more questions.