Good Morning Mohaned.
My first idea/proposal would be to write a PAM process for this.
Including webservices methods to:
-First, retrieving the location of the Catalog(SC)'s request 'requested for userid'.
-Then retrieving the 'primary contact' of that location.
-And then assign that user as the approver to the request.
However, while writing this, I am not 100% sure whether webservices methods are available to do all of the above.
Still, it is possibly, a good start for you on this.
Thanks in advance for your understanding and kind regards, Louis.