Can a creditor that placed a judgement on me and my bankrupted business come after a different business I have that's not related to this judgement?

If a judgement has been entered against YOU (which would mean that you are not being sued, but have already lost the suit), then your assets, including any interest in any other business, can be used to satisfy the judgment.  Thus if a judgment was entered based on your personal guaqranty, your assets can be used to satisfy that judgment, regardless of how the underlying obligation came about.  If the judgment has only been entered against the business and the business is an independent legal entity, such as a corporation or llc, then the judgment would only entitle the creditor to seek paymetn from the business entity, not you personally (except to the extent that monies may have been transferred out of the debtor business entity without fair consideration, which is a whole other topic).  If the business was not a separate legal entity, but was just a sole proprietorship, you are personally responsible for the debts of the business and, again, all of your assets (save those few that may be exempt, which varies depending on your state) can be used to satisfy that debt.