$FilePath = "c:/Data/C_Accounts_Group_Membership_C1-C1.csv"
$OuDomain = "OU=test,OU=abc,OU=com1,DC=com2,DC=com3,DC=com4"
$users = Get-QADUser -SamAccountName [L1-L2]* -searchRoot $OuDomain -SizeLimit 0
$users | Sort-Object SamAccountName | % {
    $user = $_ | Select-Object dn, sAMAccountName
    if ($lastDomain -eq $user.dn) {
        $lastDomain = ""
    } else {
        $lastDomain = $user.dn
    }
    $groups = Get-QADMemberOf $_ | Select-Object -expandProperty Name
    $groups | % {
        $user2 = New-Object -TypeName PsObject -Property @{
                "Domain" = $lastDomain
                "sAMAccountName" = $user.sAMAccountName
                "Group" = $_
            }
        $user2
    }
} | export-csv $FilePath