Document of Record FYI notification routing to the wrong Line Manager

Hello experts,

we have this requirement where we need to create an approval rule for document records wherein if a specific document type was created, an FYI notification will be sent to the line manager. However, if an employee has 2 work relationship, one is employee work relationship, and the other one is contingent work relationship, the fyi notification is being sent to the contingent worker work relationship line manager. The notification should be sent to the employee work relationship line manager.

I already tried to add filters in the approval to reference the employee assignment but it always give me the error