John Gill Commentary Exodus 28:27

"And thou shalt make two rings of gold, and shalt put them on the two shoulder-pieces of the ephod underneath, in the forepart thereof, close by the coupling thereof, above the skilfully woven band of the ephod." — Exodus 28:27 (ASV)

And two other rings of gold you shall make
This is the third pair of rings ordered to be made, the two other pair were for the four ends or corners of the breastplate, but this pair was for the ephod:

and you shall put them on the two sides of the ephod ;
one on the right and the other on the left:

underneath, towards the fore part thereof ;
underneath the ephod, yet towards the fore part of it; or rather on the fore part of it, though so as the rings could not be seen:

over against the other coupling thereof ;
either so as to answer to the other coupling of the breastplate to the shoulder pieces of the ephod above; or to the rings at the ends of the breastplate below, with which these were to be coupled with a lace of blue; and so the word "other" here supplied may be left out:

above the curious girdle of the ephod ;
just above that these rings in the ephod were, to answer to the rings in the lower ends of the breastplate.