Different schedules for security groups can only be set up with separate GPO's.
- Create a new schedule in the Deployment Manager interface with a new name.
- Enter all of the needed events and triggers.
- Distribute new schedule
- Create a new GPO
- In the Properties dialog, on the Security tab only have the security group that will have the new schedule
- Edit the GPO and click on the properties of the Deployment Manager node. From here you can change the applied schedule.
- Be sure to deny the above created security group for the original schedules.
- Merge Policy to apply updates.