like script, should we deploy workflow also ? if so,how to do that?

You should be able to source recipients from a field, inside that field you can add emails addresses with a comma delimiter and it should send to all. This field could be a custom field on the transaction/record the workflow is running on

the WF deployed record is PFA, the email to send is to the employees. is that possible?

Dont believe you can customise the PFA record. So you would need to see if you can get that employee record from a field somewhere on there - if it's the employee that created the PFA, you should be able to get the created from field If it's a static list of employees, you can define this somewhere else (maybe the subsidiary?) and call that field from the workflow