Q. A minyan that has only one sefer Torah for leinning on Simchas Torah, can they call two cohanim or a son after a father for chosson Torah and Bereishis?

A. Mishna Berura (135: 36) rules that one may call to the Torah reading on Simchas Torah three consecutive Kohanim for chosson Torah, chosson Bereshis and maftir, since three different sefarim are being used. He rules similarly in regards to a father and son or two brothers (141: 6, see also Nitei Gavriel – Sukos 99: 29-30 that many Poskim agree).
It would seem from the wording that the above applies only to different sefarim and not when one single sefer Torah is being used. However, Horav Shlomo Miller’s Shlit’a opinion is that since it takes time to be golel or role the sefer to the new parsha to be read, it is permitted if needed.

Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit”a