Final answer:
A person, usually a bishop, chosen by the Pope to be part of the church's leadership group is known as a Papal Appointee.
Step-by-step explanation:
The term for a person, usually a bishop, selected by the Pope to belong to a special group in the leadership of the Church is known as a Papal Appointee. This selection is part of the broader historical development of the papacy and the administrative structures associated with the Catholic Church. Not only does the Papal Appointee serve within these structures, but historically, the expansion of the pope's authority to nominate bishops and influence the broader church hierarchy has been a critical aspect of how the Roman Church asserted its influence, especially in the west where the papacy's claims to leadership eventually gained acceptance.