How can I find out where someone works to garnish his wages I live in Colorado and him in Texas

Texas does not permit garnishment of wages except under very limited circumstances.

Is this part of spousal support or part of a child support order ? I saw you posted this under divorce.

But if this is though court action, you petition the court them to tell the court where they work.

You hire a PI to follow them and find out where they work

You hire a PI to search records and see where they are being paid.