I have not seen this specific piece. However, when you see a chord written this way, you play the first 4 notes with left hand, the next four with the right and then cross over with the left to play the top note with the left index finger.
Put 8 fingers on the harp where the chord is played (except the top note in the right hand). Play the rolled chord very quickly. Practice a few times. Use the metronome to get the beat. Then when you master that, take the left hand and quickly play the top note of the right hand chord. It will work with some practice. The way the piece is written appears to call for a slower left hand and then speed up the right hand chord. But the technique is the same. You play the left hand, then right, then cross over.