noun /ˈhaɪərɑːki/ /ˈhaɪərɑːrki/
a system, especially in a society or an organization, in which people are organized into different levels of importance from highest to lowest

She's quite high up in the management hierarchy.

the group of people in control of a large organization or institution

It was on orders from the party hierarchy that she dropped the investigation.

a system that ideas or beliefs can be arranged into according to their importance

An omega male doesn't obey the social hierarchy.

It is another big change in the entertainment hierarchy.