Devices and levels in buildings
When you add a device to a building, by default, the device is associated with the default level if one has been specified. Otherwise, the device is assigned to the first level. However, you can change this and associate the device with any other level, or several levels at the same time.
More facts:
If no levels are selected, the device is visible on all levels
If you add a building on top of a device that is already positioned, by default, the device is associated with all levels
If you expand the boundaries of a building so that it covers a device that is already positioned, the device is associated only with the level that is selected
Note
If you readjust the boundaries of the building so that it no longer covers the device, the device is no longer associated with the building.