This trim piece goes on the side rear seat on the P80 Volvo station wagon estate models 850, V70, V70 GLT, V70 XC XC70, V70R vehicles. The piece is likely over 20 years old and is delicate. Left or right position is figured out by sitting in the seat, left or right from sitting in the a front seat.
It has a small chip, see photo below. It may come with the securing pins but will NOT come with the pin inserts. I usually use small shish kabob skewers to secure mine. Stick one in and break it off then color it black with a sharpie.