US Gov't bureaucracy

I work in Canadian government, in which as a Senior Officer I oversee a couple of junior officers. I answer to a Director, who answers to a Director General, who answers to an Assistant Deputy Minister, who answers to a Deputy Minister, who (i) is the senior civil servant in any federal gov’t department, (ii) answers to the Clerk of the Privy Council, who is the senior civil servant in the country. The Deputy Minister also functions as senior secretary/advisor to a cabinet minister. The Clerk of the Privy Council is secretary to the whole Cabinet. Anyone familiar with 80’s brit-com Yes, Minister will see that our system is based largely on British system.

All of this is a long lead-up to a simple question . . . What is the equivalent US hierarchy?

Well the American (civilian) bureaucracy isn’t quite as organized. Regarding the Executive branch:

The President

The Cabinet has a Secretary for each Department. Each Secretary has undersecretaries for various divisions in their departments. The departments are divided into various beareaus and agancies, usually overseen by a Director. Beyond that, it’s anyone’s guess.