Get navigation nodes from top navigation in hub (3 levels)

Question

I'm using PowerShell ISE and SharePointPnPPowerShellOnline to get the TopNavigationBar navigation nodes from a hub site. I want all nodes in all levels. The navigation is 3 levels as you can see on the picture:

My code is able to get 2 levels if I comment out the last if check etc, but not the 3 level nodes, and I get an error message.

An error occurred while enumerating through a collection: The collection has not been initialized. 
 It has not been requested or the request has not been executed. It may need to be explicitly requested..
At C:\Users\some.name\scripts\getNavigationps1:24 char:15
+ ...             $subChild = $child.Children | Select Title, Url, Id
+ CategoryInfo          : InvalidOperation: (Microsoft.Share...NavigationNode]:<GetEnumerator>d__0) [], RuntimeException
+ FullyQualifiedErrorId : BadEnumeration
The collection has not been initialized. It has not been requested or the request has not been executed. It may need to be explicitly requested.
getNavigation-Ingrid.ps1:26 char:23 foreach($subChild in $child.Children)

Is there something wrong in my logic/"code"?

Connect-PnPOnline -Url "https://xxxxxx.sharepoint.com/sites/testhub2"
$TopNavs = Get-PnPNavigationNode -Location TopNavigationBar |Select Title,Url, Id


foreach($TopNav in $TopNavs)
{
    $node = Get-PnPNavigationNode -Id $TopNav.Id 

    Write-Host
    Write-Host "TopNav_Id: [" $TopNav.Id "]" "Title: " $TopNav.Title "Url: " $TopNav.Url
    Write-Host

    if($node.Children)
    {
        $child = $node.Children | Select Title, Url, Id     #gets topnavs children

        foreach($child in $node.Children){

        Write-Host "   ++ child_Id: [[ " $child.Id"]]" "Title: " $child.Title "Url: " $child.Url
        Write-Host

        if($child.Children)
        {
          $subChild = $child.Children | Select Title, Url, Id   #gets childrens children

          foreach($subChild in $child.Children)
          {
            Write-Host "     ++ subChild_Id: " $subChild.Id "Title: " $subChild.Title "Url: " $subChild.Url
          }
        }
        }
    }
}

Appreciate any thoughts and answers!

Answer 1

You need to request the sub-sub child data again using Get-PnPNavigationNode command.

Modify your code as below:

$TopNavs = Get-PnPNavigationNode -Location TopNavigationBar |Select Title,Url, Id


foreach($TopNav in $TopNavs)
{
    $node = Get-PnPNavigationNode -Id $TopNav.Id 

    Write-Host
    Write-Host "TopNav_Id: [" $TopNav.Id "]" "Title: " $TopNav.Title "Url: " $TopNav.Url
    Write-Host

    if($node.Children)
    {
        $child = $node.Children | Select Title, Url, Id     #gets topnavs children

        foreach($child in $node.Children){

        Write-Host "   ++ child_Id: [[ " $child.Id"]]" "Title: " $child.Title "Url: " $child.Url
        Write-Host

        #get 3rd level terms
        $subChildNode = Get-PnPNavigationNode -Id $child.Id 

        if($subChildNode.Children)
        {
          $subChild = $subChildNode.Children | Select Title, Url, Id   #gets childrens children

          foreach($subChild in $subChildNode.Children)
          {
            Write-Host "     ++ subChild_Id: " $subChild.Id "Title: " $subChild.Title "Url: " $subChild.Url
          }
        }
        }
    }
}