Are you are doing stock removal?
Besides actually forging in the look, there are a couple ways to get something like it.
1) You can use carbide ball burrs and Cratex wheels to "carve" the pattern.
2) You can grind the upper bevel with a coarse belt and then finish the lower bevel with much finer grits.
3) Shot blasting and/or coarse sandblasting.
After HT, don't do anything with the upper area to keep it dark.
You can also etch in FC or other chemicals to darken the top pattern.