@Anonymous
You can't use the equal sign, pipes, etc.. You must use operators such as equals(), or()
I may have missed a paren somewhere, but it should look something like this:
if(or(equals(triggerBody()?['Author']?['mail'],employee1@gmail.com),equals(triggerBody()?['Author']?['mail'],employee2@gmail.com)),specificemail@gmail.com, body('Get_manager_(V2)'?['mail'])