In the same building, my brother lives in the room directly below my brother. Is this appropriate from the perspective of geomantic omen?

Whether it is suitable or not depends on the changes in the external structure of the house. For example, there is a house in the fierce direction, and the height of the house is just the height of the younger brother's house, which will only affect the younger brother but not the older brother. Second, it depends on the decoration of the house. Third, it depends on the fit between the inner and outer mountain patterns and the eight characters. Feng Shui is a science, not an ethics. If it doesn't exist, it must be above my brother's house. It's not a haunted house, and there's no such pressure.