It is to have two shoulder-pieces attached to its two edges so it can be joined together.

They made connecting shoulder pieces for the ephod and attached them to its two edges.

and they attached the other two ends of the two cords to the filigree settings, and then attached them to the shoulder pieces of the ephod in front.

They made two gold rings and attached them to the two edges of the breast piece, on the side of it which is toward the inner side of the ephod.

They made two gold rings and attached them in front, on the lower part of the two shoulder pieces of the ephod, close to the place where it's joined, above the skillfully woven band of the ephod.