senior leadership; top executives; upper echelon
Refers collectively to the highest-ranking officials or leaders in an organization, government, or military. Can also refer to an individual top-ranking officer.
The company's senior leadership held an emergency meeting.
He is one of the top-ranking officers in the police force.
幹部 means 'executive' or 'management' in general, while 最高幹部 specifically refers to the very top tier of leadership.
上層部 also means 'upper management' or 'higher-ups', but 最高幹部 emphasizes the absolute highest level, often with decision-making power.
Compound of 最高 (highest) and 幹部 (executives, management).