Question

in one particular lesson something happens in the hotel but the name of the lesson is titled THE NIGHT AT THE HOTEL my point is when something happens inside the hotel during night time why the preposition IN is not used rather than AT will you please clarify

Answer 1

If "in" is used, then the meaning is that whatever occurred was INSIDE the hotel.

When "at" is used, whatever occurred could have been inside or outside the hotel ... or maybe both.