Hey guys i want to know the best place for dball hunting for lvl 30-38 hk though.

I just got all seven of mine hunting from the first part of the level 31 mobs and those robots on that cliff. I recommend those spots as the mobs are docile, as in they won't attack unless you attack, which makes searching for the Dragon ball mob a lot safer.

every place where u alone and the monsters are lvl or 2 lvl more from u

Outside of UD2, you should see a whole bunch of supers, about level 39. Kill a bunch of them and wait for them to re-spawn. You should see a few Dragon Ball mobs pop up. Kill those. Keep repeating this process and complete a set of DBs. Once you are level 40ish, try going to that tower in the north part of the third region. It's a small mountain with super wolves. Do the same process as I explained earlier. I got a whole set of DBs in two days using this method. Please thank user if I helped. :)

You should look for some 'Supers' or 'Crates' on the map, which are of your level. Their drop rate is 10% more.