From what I can see, you should be able to simply update your text file so instead of having “SG-PROD-Kit” for the TargetGroup, for example, it says “ProductionDomainName\SG-PROD-Kit”. Alternatively, you could prepend the “ProductionDomainName\” string in your PowerShell code, if you prefer:
$TargetGroup = "ProductionDomainName\$($Group.TargetGroup)"