。
She demanded to see the manager.
Literal
She [topic-は] manager [to-に] meet [nominalizer-こと] [object-を] demanded.
Demanding to see the manager is a common customer-service scene. Structurally: 会うこと ('the act of meeting') is nominalized via こと, then taken as the object of 要求する. 会う takes に for the person met — 支配人に会う ('meet the manager'). 要求する ('to demand, to claim as a right') sits a notch above 頼む ('to ask') in social weight: it implies entitlement, not request.