Based on the screenshot you have posted, the itemclick event should be something like this if you click on titem 3:
Private Sub CustomListView1_ItemClick (Index As Int, Value As Object)
Dim item As CLVTreeItem = Value
Log("Item 3 (son) " & item.Text) 'displays item 3
Log("Item 2 (father) " & item.Parent.Text) 'displays item 2
Log("Item 1 (grand father) " & item.Parent.Parent.text) 'displays item 1
End Sub
However, if you want to be able to click on any level, not just 3 to avoid a crash, you need to involve the Item.tag. to differentiate between the levels If you need help with that, come back.