Usa alias per assegnare nomi:
CREATE VIEW v_payment AS
SELECT p.payment_id, c.first_name as customer_first_name, c.last_name as customer_last_name,
s.first_name as staff_first_name, s.last_name as staff_last_name,
p.amount
FROM payment p INNER JOIN
customer c
ON p.customer_ID = c.customer_ID INNER JOIN
staff s
ON p.staff_ID = s.staff_ID;
first_name
e last_name
appaiono due volte nella tua select
elenco. Quanto sopra chiarisce se il nome è per un cliente o per il personale.