Extract-XPaths.ps1

Clear-Host
function Extract-XPaths {
    [CmdletBinding()]
    Param (
        [Parameter(Mandatory = $true, ValueFromPipeline = $true)]
        [System.Xml.XmlElement]$elem
    )
    Process {
        [string]$name = $elem.LocalName
        $name 
        $elem.Attributes | ?{($_.Name -ne 'xmlns') -and ($_.Name -notlike 'xmlns:*')} | %{'@{0}' -f $_.Name}
        $elem.ChildNodes | ?{$_ -as 'System.Xml.XmlElement'} | Extract-XPaths | %{Join-Path $name $_}
    }
}

[xml]$x = @'
<?xml version="1.0" encoding="utf-8"?>
<sch:RootElem xmlns:sch="http://schemas.example.com">
    <sch:Demo1>
        <sch:ChildElem myAttribute="5">
            <sch2:GrandChildElem xmlns:sch2="http://schemas.example.com/2">
                <GreatGrandChildElem xmlns="http://schemas.example.com/3">
                    <Node />
                </GreatGrandChildElem>
            </sch2:GrandChildElem>
        </sch:ChildElem>
    </sch:Demo1>
    <sch:Demo1>
        <sch:Hello />
    </sch:Demo1>
    <sch:Demo2>
        <sch:Hello>World</sch:Hello>
    </sch:Demo2>
</sch:RootElem>
'@
$x.DocumentElement | Extract-XPaths 

<#
  Outputs:
    RootElem
    RootElem\Demo1
    RootElem\Demo1\ChildElem
    RootElem\Demo1\@myAttribute
    RootElem\Demo1\ChildElem\GrandChildElem
    RootElem\Demo1\ChildElem\GrandChildElem\GreatGrandChildElem
    RootElem\Demo1\ChildElem\GrandChildElem\GreatGrandChildElem\Node
    RootElem\Demo1
    RootElem\Demo1\Hello
    RootElem\Demo2
    RootElem\Demo2\Hello
#>