。
I saw the train pull into the station.
Literal
Train [topic-は] station [into-に] pulling-in [object-を] me [by-に] was-seen.
A passive construction that flips the natural 'I saw the train' to 'the train was seen by me.' 私に by-marking of the agent is formal/written. Inside the passive: 駅に入ってくる is a perception-complement — 'the train coming into the station.' 入ってくる (enter + come) indicates motion toward the speaker's viewpoint. This is the 'direct perception' complement structure, where the thing perceived is marked with を, not a subordinate clause.