When referring to a Sephardic Rabbinical leader should he be referred to as Rabbi So and So or as Chacham So and So?
Unless you know this particular Rav is also considered a big talmid chacham, probably safer to be respectful and just call hin “Rav”
I think the question is what your title for them is, not their official title.
(In other words, it’s whether you, not the Rav, is Ashkenazi or Sefardi.)
Random: Are you implying that a Sephardi will call him Chacham whereas an Ashkenazi will call him Rabbi?
A woman sat next to an Ashkenzai rosh yeshiva on a bus. He moved and there was a big argument. The next day she sat next to a Sephardi rosh yeshiva. Hedidn’t move nadshe got off at the next stop disappointed. When asked about it he said “Hu rav. Ani chacham”.
BTW, in Germany there was a designation “Chaver” which YU revived forty years ago. I heard about someone who insists on being called to the Torah as “ben haChaver”.