The center of the hole appears appears to have an offset from the external radius. You can use a rotary table to mill the outside radius, then offset the center of the table whatever distance the hole is offset from the outer radius. Then install the hole. There appears to be a thin wall between the arcs, so you may want to do it in reverse order, whichever way is less likely to deform the work piece. Or fill the hole, then cut the outer radius.
Or farm it out. lol