It would need major surgery. If it was my favorite bow, I would grind out the flaw and feather back into the good wood about 4-5" either side. I would use a urea formaldehyde glue, and glue in either a carefully shaped piece to fit the repair or several thin flexible pieces that will conform to the shape of the repair.
Trim the excess off, and retrain the bow to bend slowly, so the new wood can get accustomed to bending.
Not an easy repair, especially if you aren't experienced