second door from here; next door but one
Refers to the house or location that is two doors away, not the immediate neighbor. Often used in contexts like giving directions or describing a nearby place.
The post office is two doors down, straight along this road.
His house is the second door from ours.
Compound of 又 (mata, 'again; further') and 隣 (tonari, 'next door'), literally 'next-door again'.