I found that the easiest place to get this achievement was on Level 3 - "Level Zero", which is the training room level. You will get instructions from Master Shifu and to progress you must follow his instructions by doing the required hit/melee combo.
Early in the level you will encounter a triangle of training dummies (6 in total) and be asked to perform an X,Y combo to juggle them. DON'T!! Instead of doing this use your hard punch Y on them. For every dummy you hit, it will add 1 to your Hit Chain (bottom corner of screen) so 5 punches should do.
Don't worry if you miss and fail on Hit Chain and it resets, just destroy the rest of the dummies with punches (BUT DO NOT X,Y JUGGLE) and a new bunch will re-spawn to try again.
(For your information, these dummies are also useful to gain thousands of gold coins with. If you have activated Unlimited Chi cheat then just Panda stumble through them and in approx 10 mins you should have enough gold to unlock all upgrades and outfits)