sorting curves by proximity or containment of another curve

I am working with a metaball script. I am forced to flatten the imput curves and points in order to get a decent output of the metaball. the problem is i want to be able sort the curves so i can create a facade from it using points on those curves. so i am trying to resort the curves after and rebuild an ordering system.

anyway, so my question is: does anyone have any ideas of how to sort the curves (red) into 4 separate lists, bases on either their proximity  or containment of the curve they are based off of (green).