What are the levels of bureaucracy at the national level?

I am assuming by level, you mean level of government. There is no distinction between government on a national level and government on a federal level. The federal level of government is the highest...

The amendments are approved at the national level usually by congress and proposed to the states.

the government that takes care of things that need to be done state wise.

The defense of people and territory is widely viewed as the first duty of government, and in almost all cases is administered by the national level of government. In the United States, for example,...

It means the level of the entire country