Yes, deep underground shelter planned for nuclear attack will be enough to survive, as damaging mechanisms, are mostly same - short but very powerful infrared flash and deadly shockwave (better to consider it as very fast pressure grow and then pressure drop).

Just staying behind hill, will be not enough cover from shockwave, so people will suffer from fast pressure changes.

But shockwave quickly weakened as square of distance, and hill will make it's path longer. So, something like 100m hill could be considered as moving border of deadly zone 100m closer to epicenter.