$domain = [system.directoryservices.activedirectory.domain]::GetCurrentDomain()
$domainde = $domain.GetDirectoryEntry()
$dcs = $domain.FindDomainControllers()
$DCGroups = @{}
foreach($dc in $dcs)
{
    Write-Host " + Processing DC $($dc.Name)"

    $myGroupObjs = @()

    $searcher = $dc.GetDirectorySearcher()
    $searcher.PageSize = 1000
    $searcher.Filter = "objectcategory=group"
    foreach($result in $searcher.FindAll())
    {
        $MyGroupObj = "" | Select-Object GroupName,GroupMembers

        $myGroup = $result.GetDirectoryEntry()
        Write-host "   - Processing Group $($myGroup.Name[ 0 ])"
        $members = $myGroup.psbase.invokeGet('member')
        $MyGroupObj.GroupName = $myGroup.Name[ 0 ]
        $MyGroupObj.GroupMembers = $members

        $MyGroupObjs += $MyGroupObj
    }
    $DCGroups.Add($dc.Name,$MyGroupObjs)
}
$DCGroups