Twenty-second Amendment to the United States Constitution
Some argue that the 22nd Amendment and 12th Amendment bar any two-term president from later serving as vice president as well as from succeeding to the presidency from any point in the presidential line of succession. Others contend that the original intent of the 12th Amendment concerns qualification for "service" (age, residence, and citizenship), while the 22nd Amendment, concerns qualifications for "election", and thus (strictly applying the text) a former two-term president is still eligible to "serve" as vice president (neither amendment restricts the number of times an individual can be elected to the vice presidency), and then succeed to the presidency to serve out the balance of the term (though prohibited from running for election to an additional term).
2022 German presidential election
Every member of the Federal Convention (members of the Bundestag and state electors, once they are elected by their respective state parliament) can propose candidates for the presidency. It is required that the President is a German citizen and at least 40 years old. Every candidate has to declare his consent to running. Candidates can be proposed before the Federal Convention and (theoretically) during the Convention before every ballot. If the President-elect is a member of a legislature or a government on federal or state level, he has to resign from that office before the start of his term. A sitting President is not allowed to run for a third "consecutive" term.