Refers to someone in a higher position at work, in an organization, or in a hierarchy.
I'll decide after consulting my superior.
them (as opposed to us); the elite; those above
Used to contrast ordinary people with those in power or higher social status, often with a sense of distance or criticism.
person above; upstairs neighbor
Refers to someone physically above, such as an upstairs neighbor or a person on a higher floor.
The people at the top only ever think about themselves.
The person upstairs is walking around until late at night.
A straightforward compound of 上 (うえ, 'above') + の (possessive particle) + 人 (ひと, 'person'). The phrase is transparent and follows standard Japanese grammar.