Bill will answer better about this particular pattern, but most all more elaborate patterns require a press at a minimum. A power hammer is a good addition, too. Doing flips and stacks by hand is "possible", I guess, ....but unlikely to have a good success rate. It would kill my arm even to try.
For hand hammered damascus, stay with patterns that are layered and manipulated. There are many ways to get unique patterns that are similar to mosaic damascus and other patterns. I'll give a few ideas to get you thinking.
1) Get a set of 3/8" or 1/2" letter stamps. Once the billet is layered to the desired layer count ( 200-500 is good), grind it clean on the surfaces. Stamp the hot billet with the letters "D.ELLIS", e.g., to the same depth you would do a birds eye or ladder pattern divot. Do this in a row down the center, all over at crazy angles, or just at the ricasso ( your choice). Do it from both sides. Grind down the billet to the depth of the stamps and when you etch, the letters will show as disturbances in the pattern ( like a bird's eye pattern does). If done only at the ricasso or once at the upper sine near the ricasso, it creates a damascus makers mark in the blade pattern.... a really cool effect.
2) Similar to above, but simpler, is to make a stamp of a fairly simple shape out of round or square steel rod - a cross, a diamond, an asterisk, a question mark, a butterfly, etc. Use it as above to make "butterfly damascus", mystery steel damascus (?), etc.
3) Do a standard technique in a non-standard way. Do a ladder pattern at a diagonal, or in a "X" pattern.
4) Make your billet of random damascus up in the size needed to make a desired knife. Leave it a tad thicker than your final need. Drill a series of holes down what will be the upper bevel area or down the center line ( you decide where it will look best). Make the holes descending in size starting with the largest at the ricasso area and going about 3/4 of the way toward the tip area. Say, six holes 1/2, 7/16, 3/8, 5/16, 1/4, 3/16. Using a steel compatible with the damascus mix, grind or turn plugs for the holes and forge weld the plugs in. When ground and shaped into the blade you will have smooth round circles descending down the damascus blade.
. Does anyone here know how it is done? I know J.R.Cook makes it, and maybe a couple other smiths, but can't find any other info. Maybe it's a trade secret? It sure does look cool seamlessly blending 2 different patterns like that.
Even if I can only manage a smallish blade, it'll be worth it at least once or twice.