You're certainly right that the greens were founded later, but the liberals existed as a party at the times of Hitlers rise to power. There were no other major parties in Western Germany.
However, we both might want to reread our history books a bit. One crucial step in the Nazi coup was the Enabling Act of 1933 which gave the NSDAP or rather Hitlers Cabinet - despite not having a majority in the parliament - the right to pass laws. The communists had been suppressed before and could not vote and I remembered that the SPD abstained. That's where I'm wrong - they voted against, at least those present. Some were not present at the vote. The rest of the parliament, including the Zentrum and the Liberals (which had 5 seats) voted in favor, granting the required 2/3 majority. Many Zentrum members, including the head of the party at that time were strict nationalist. Other members voted under duress. So yes, the Zentrum had a part in the dealing that brought Hitler to power. See https://en.wikipedia.org/wiki/Enabling_Act_of_1933 and https://de.wikipedia.org/wiki/Erm%C3%A4chtigungsgesetz_vom_2...
There's a fairly interesting list of Ex-NSDAP members that after the war joined other parties. https://de.wikipedia.org/wiki/Liste_ehemaliger_NSDAP-Mitglie... (among them Filbinger, and, notably, Hans Furler, President of the European Parliament and Genscher, the Exterior Minister at the time of the Reuinion)