Sending email to account owner's supervisor from AFX fulfillment workflow

I have a situation where email needs to be sent upon account disablement to the account owner's supervisor from the  default AFX workflow extended with an email node. I assumed it could be done filling in from Object->Users->Supervisor (email) (see screenshot). However, this does not work. Is it possible to assign the supervisor's email address within the email node without adding SQL query node?

TIA.