DelegateExpense ReportDFF(Default Value) not populating based on the Owner but based on Creator

Summary: we Created DFF(Based on Default - SQL) to default the Supervisor based on the Expense report owner.

Content (required):

e.g User A - Expense Report Owner , User B - Delegate(creating expense report on behalf of UserA)

User C - Supervisor of User A, User D - Supervisor of User B.

Scenario: UserB is creating Expense report on behalf of User A, expectation is to have the DFF Supervisor name of User A which is UserC.

we used the FND_GLOBAL.USER_GUID variable to get the Expense report user id to be used in Default SQL Query(attached), such that userid is mapped to userid variable in query and derived the Supervisore name value. this works as expected when the creator is same as the Expense report owner, but when delegates created the Proxy Expense report, the DFF is defaulting the supervisor name of the Creator(User D )rather than Owner Supervisor of Expense report User C.