Borges was influenced by Nietzsche's ideas, in particular his "eternal return" (see The Doctrine of Cycles) and mentions him explicitly in some of his stories (e.g. Deutsches Requiem). What I have only recently realized is that Borges' story Funes the memorious (already mentioned in a previous post) is prefigured in Nietzsche's second Untimely Meditation1:
Imagine the extremest possible example of a man who did not possess the power of forgetting at all and who was thus condemned to see everywhere a state of becoming: such a man would no longer believe in his own being, would no longer believe in himself, would see everything flowing asunder in moving points and would lose himself in this stream of becoming: like a true pupil of Heraclitus, he would in the end hardly dare to raise his finger.
Nietzsche's has already been invoked in relation with Funes2, but as far as I can tell (I do not have access to the full text of the paper) only with respect to the difficulty of forming general concepts.
1. Breazeale, D., & Hollingdale, R. J. (1997). Nietzsche: Untimely meditations. Cambridge University Press.↩