verb
to take a back seat, to play second fiddle, to be on the back burner, to fade into the background
“Aparte de él, aquí he tenido varios profesores que han ayudado a vencer mis confusiones. Aquello ha pasado a un segundo plano.” — Apart from him, I have had several teachers here who have helped me to overcome my confusions. That one has taken a back seat.
Compare French passer au second plan.