The book claims to be a recursive relationship.
I think it's possible to make a comparison with the example
I made a drawing on draw.io to represent the answer.
InthiswayitispossibletorepresentthatthereareNclientsthatreceiveremunerationfromotherclients,andthatthereisatleastoneclientthatassumesthepositionofremunerator.
Notethatthenumber"1" on the payer's side indicates that in a transaction there can only be one person who is paying the other, that is, not for 2 or more people to make a payment for the same person in the form of a single record (this does not make sense)
If a (paid) person is receiving an amount of more than one (remunerative) person, then there must be 2 separate payment records.
The answer came from the book: Database Systems 5th Edition
Authors: Elmasri, Ramez Navathe, Shamkant B.
Year: 2011