How long will the creditor or lawyer look for other bank accounts, if
A levy was placed on one bank account already?

If there is more than one bank account and the first levy does not satisfy the judgement then its just a matter of time before they will locate it.

A collection company looking will run a new credit report every so often, to see if a new bank did a check on you ( sign of possible account)
Also there are some areas they pay for, that give additional search ability