Anyone who owes you "the debtor" funds, or if someone else holds money on behalf of your debtor, they are considered a "garnishee defendant". Using a garnishment process, it is possible to force the "judgment debtor's" current employer to reveal to the court how much money they are holding or owes to the debtor.
Once you know the actual employer where your subject "the debtor" is gainfully employed, you can obtain a Writ of Garnishment form and have a court force the debtor's employer to pay a certain part of the funds owed to the court. After the court receives the payments, the court would turn the funds over to the judgment holder.
To obtain a Writ of Garnishment for wages, you'll need to know where your debtor works so you can file the garnishment action. Filing the writ of garnishment may cost a small fee plus the costs of serving the associated papers to the employer. SeachBug investigator services can help to locate the place of employment and if successful, you can try to recover some of the costs as part of the judgment you are collecting. Check with your local court to be sure.
Note that an employment garnishment for wages can only attach disposable earnings, the amount or percentages you may receive is set by state law, be sure to ask the court clerk for the correct amount to make sure it's worth the effort if your subject is in a low paying job, changes jobs often or is self-employed.