As a recent example, the recent $2.3 trillion stimulus bill contained not just provisions related to supporting the American people, but also a requirement to produce a report on UFOs:
Federal agencies have been asked to publish a report on unidentified flying objects (UFOs) in less than 180 days, thanks to an act included in the $2.3 trillion stimulus and government spending bill signed by President Donald Trump on Sunday.
A report by the Select Committee on Intelligence attached to the The Intelligence Authorization Act for 2021 states that the Director of National Intelligence, the Secretary of Defense and the heads of other relevant agencies submit a report to the congressional intelligence and armed services committees on "unidentified aerial phenomena (also known as "anomalous aerial vehicles''), including observed airborne objects that have not been identified." They are asked to do this 180 days after the act is enacted.
Are there countries where a law may only focus on one single topic?