Replace Value Based on Compound If Statement.

Solved my issue:

= Table.ReplaceValue(Source,each [Supervisor],
each if [Supervisor]="Not Assigned/Non affecté Not Assigned/Non affecté" and [Worker]="Sue" then "Ralph"
else if [Supervisor]="Not Assigned/Non affecté Not Assigned/Non affecté" and [Worker]="Anna" then "Stan"
else if [Supervisor]="Not Assigned/Non affecté Not Assigned/Non affecté" and [Worker]="Pete" then "George"
else [Supervisor],Replacer.ReplaceValue,{"Supervisor"})

= let sup = Record.FromList({"Ralph","Stan","George"}, {"Sue","Anna","Pete"}) in Table.ReplaceValue(Source, each [Supervisor], each if [Supervisor]="Not Assigned/Non affecté Not Assigned/Non affecté" then Record.FieldOrDefault(sup, [Worker], [Supervisor]) else [Supervisor], Replacer.ReplaceValue, {"Supervisor"})