There’s also the Palatinate branch of the Habsburgs, the ones who served as Palatines governors to HungaryHe is Archduke Karl of Austria, Prince of Hungary, though I don't think he has ever made any claim to any throne.
Archduke Karl is the eldest son of the late Archduke Otto, Crown Prince of Austria and of Hungary, himself the eldest son of the last Emperor of Austria and King of Hungary Karl I.