There are actually two additional tiers. One are secret courts like FISA, which while they are (arguably) legal, lack sufficient oversight. And extrajudicial courts, which while (arguably) NOT legal, have very stringent oversight.

An extrajudicial court formed by executive order to handle cases of individuals and organizations that operate above the law. With oversight by select members of congress, military, and the president.

Some call it a star chamber. I view such things as necessary.