Final answer:
The Commanding Officer is the one who regulates leave and liberty in the military's chain of command. They oversee their subordinates and are part of a strict hierarchical system governed by rules, such as those outlined in the U.S. Constitution.
Step-by-step explanation:
The person in the chain of command who regulates leave and liberty is the Commanding Officer. Hierarchies of authority are common in various organizations, including military institutions, where there is a clear structure and chain of command. In the military, the commanding officer has the ultimate authority over their subordinates and is responsible for granting leave and managing the daily operations of their unit, reflecting a strict adherence to the chain of command as defined in military protocol and underpinned by legislation such as Section 2 of the U.S. Constitution that establishes the President as Commander in Chief of the armed forces.