Hi Blake, as a workaround; you can have a field on your form that is hidden which will contain a value from a lookup whether the logged-in user is a supervisor or not.  Have a database table with a column list of the supervisors (as you suggested) and a second column with a value such as "Supervisor" next to each entry.  When the user logs in, a read-only field can be auto-populated with the user account which can trigger a lookup rule to query this table. If the user is in the list, it will populate the hidden field with the column value "Supervisor".

Now in your process, just have an outflow condition checking to see if that hidden field contains the value "Supervisor".

This method can be used for other scenarios as well, such as if you have a database table list of all employees in the organization with a column detailing their job position.  The hidden field (or not hidden) will be populated with their position, and then you can have multiple outflow conditions to determine how to handle the form submission based on their job position.