Build Directory from Treenodes

What I am trying to do is build a directory path from the children of a selected Node. But it seems the code I have forgets a few nodes and the path is not being built correctly.

Tree Structure

Treenode1(SelectedNode
---------NodeB
--------------NodeB Child
--------------NodeB Child
---------NodeC
---------NodeD
Treenode2

My code

 Private Function GetSelectedNode_Children(ByVal SelectedParentNode As TreeNode)
        BuildDirNode(SelectedParentNode)
        If SelectedParentNode.GetNodeCount(True) > 0 Then
            For Each childnodes As TreeNode In SelectedParentNode.Nodes

                BuildDirNode(childnodes)
           
                If SelectedParentNode.GetNodeCount(True) > 0 Then
                    GetSelectedNode_Children(childnodes)
                End If

            Next
        End If
End Function

 Private Sub BuildDirNode(ByVal nd As TreeNode)

        ExportPath = ExportPath & "\" & nd.Text
        If Not System.IO.Directory.Exists(ExportPath) = True Then
            System.IO.Directory.CreateDirectory(ExportPath)
            'Do file stuff here
        End If

 End Sub

I have tried using the nodes in a collection but the same end result. Please Help