Once I have created floors using the Level Manager, how can I switch from one floor to another?

To switch from one floor to another, double click on the desired level from the Level Manager panel _vaLevels.

When you do that, the rest of levels contained in the same building remain hidden and locked.

Take into account that you can turn on/off the visibility of other levels without leaving the current level which you are working from. And in the same way it is possible to lock/unlock other levels for small changes or blocking the edition of these levels.