The metod is similar as shown in this tip, but for cutting floors you need a dummy element imported as a staircase, not door or window.

I've just uploaded a file with two elements like this I'd made for myself - see here. This is a library file, so import it as library and you'll find a cutting cylinder and a cutting cube in a folder named "construction". Put the cylinder in the basement and elevate it so it goes through the ceiling, then you should see a hole on the first floor. Resize the cylinder and modify the material to invisible.