At home, which room the eldest brother sleeps in, there are four rooms upstairs and downstairs. Does this have anything to do with Feng Shui?

It is not the head of the household who lives in the upper house, but the senior elder. If parents or grandparents are present, the eldest brother does not have the right to live in the upper room, but the younger brother should live under the older brother. For a house facing north and south, the east side is at the top. If there are elders on the first floor, the eastmost room belongs to the elders, otherwise it belongs to the eldest brother. The first floor is larger than the second floor, and the east side is larger than the west side. Just follow this principle.