Pics would really help!

I have a J mold liner, the way that works is that a heavier gauge white vinyl upside down J or V is welded to the liner, it overhangs the top of the wall, a groove in my top channel (resin) fits over that to help hold it in place.

A beaded liner would actually have a bead that clips into the receiver, I believe the bead is a harder milk jug type plastic and has burred edges to keep it in place, it just clips into to the C shaped receiver that is hung from the top edge of the wall.

Sounds to me like you got a J mold liner and they used the beaded liner receivers as clips to hold the J on.

Questions regarding the hole that may help us narrow down it's location:
- You said it was there since last year - how much did your water level drop over the course of the winter? Usually, your pool will drain to the height of the hole or within an inch of it. Now you only have to search at that height around your pool.
- do you have drop in steps? - reason I'm asking this si many people poke a hole or two in the liner when removing the steps, so looking in/around the area of where your steps are is another good starting place. Even non drop in steps can damage liners just from the rubbing they tend to do.

If the pool store allready ordered a liner and you're pretty determined to just replace it, the beaded liner should match your existing bead receiver