Please How to use code fences
It would be helpful to understand what you’ve tried. All you do is define the Group using Group:Switch and the Group will be a Switch Item. You may want to give it an aggregation function, such as Group:Switch:OR(ON,OFF) which will make the Group’s Item be ON if one or more of the Group’s members are ON.
Sending a command to this Group will forward the command to all of it’s members. But that requires all the members to accept the same commands. You can’t mix Switches and Rollershutters because Rollershutters don’t accept ON/OFF commands.
So you will need to use a Design Pattern: Proxy Item and Rule to change the ON command to a DOWN command for the Rollershutters.