Get-ADObjectParentPath.ps1

Function Get-ADObjectParentPath {
<#
    .SYNOPSIS
        Get the parent DN location of an AD object.

    .DESCRIPTION
        Get the parent DN location of an AD object.

    .PARAMETER DistinguishedName
        DistinghedNames objects passed as input (from AD cmdlets).

    .PARAMETER DN
        DistinghedNames strings passed as input

    .EXAMPLE
        Get-ADUser Skywalker | Get-ADObjectParentPath

    .EXAMPLE
        'CN=Luc Skywalker,OU=Users,OU=Prod,DC=Star,DC=Wars,DC=com' | Get-ADObjectParentPath
#>
[CmdletBinding(DefaultParameterSetName = 'String')]
Param(
[Parameter(ParameterSetName = 'Obj', Mandatory,ValueFromPipelineByPropertyName)]
[ValidateNotNullOrEmpty()]
$DistinguishedName,

[Parameter(ParameterSetName = 'String', Mandatory,ValueFromPipeline)]
[ValidateNotNullOrEmpty()]
[string[]]$DN
)
Begin {

    if (-not(Test-Path -Path 'AD:\' -PathType Container)) {
        Write-Warning -Message 'Failed to find the AD drive, aborting'
        break
    }
}
Process {

    if ($DistinguishedName) {
        $DistinguishedName |
        ForEach-Object -Process {
            $parent = ((Get-Item "AD:\$($_)" -ErrorAction SilentlyContinue).PSParentPath |  Split-Path -NoQualifier ) -replace '//RootDSE/',''
            if ($parent) {
                $parent
            }
        }
    }
    if ($DN ) {
        $DN |
        ForEach-Object -Process {
            if (Test-Path -Path "AD:\$($_)" -ErrorAction SilentlyContinue) {
                $parent = ((Get-Item "AD:\$($_)" -ErrorAction SilentlyContinue).PSParentPath |  Split-Path -NoQualifier ) -replace '//RootDSE/',''
                if ($parent) {
                    $parent
                }
            } else {
                Write-Warning -Message "Path AD:\$($_) not found"
            }
        }

    }
}
End {}
}