Copy AD group

$Source_Group = "CN=Group,OU=Unity,DC=example,DC=com" 
$Destination_Group = "CN=Group,OU=Unity,DC=example,DC=com" 
 
$Target = Get-ADGroupMember -Identity $Source_Group 
foreach ($Person in $Target) { 
    Add-ADGroupMember -Identity $Destination_Group -Members $Person.distinguishedname 
}