Only know 1st participant/recipient

Is it possible to construct an agreement, with only the first recipient's (participant 1) email address being specified, that will allow participant 1 to enter the email address of the remaining participants? Say, for example, that we have 200 employees in 10 separate sections of a company who need to sign an agreement, along with their respective supervisors and directors (so the signing order would be simple: Participant1, Participant2, and Participant3). We can easily send the agreement to the email address of each employee (Participant1), but we don't necessarily know the chain of command of each section; however, the employees do. If we could send the agreement to Participant1 with instructions to enter the email addresses of their supervisor and director in that order, we could collect the signatures we need without much additional work.