It would be helpful if you posted a sample of your xml file, but here is an example based on this xml.
="1.0"="utf-8"
<groups>
<group Name="Administrators"></group>
<group Name="Editors">
<User_Initials>abc</User_Initials>
<User_Initials>zyz</User_Initials>
</group>
<group Name="Guests"></group>
</groups>
Dim doc As New Xml.XmlDocument
doc.Load("xmlfile1.xml")
Dim groups As Xml.XmlNodeList = doc.SelectNodes("./groups/group")
For Each grp As Xml.XmlElement In groups
Dim node As TreeNode = TreeView1.Nodes.Add(grp.GetAttribute("Name"))
For Each user As Xml.XmlNode In grp.SelectNodes("./User_Initials")
node.Nodes.Add(user.InnerText)
Next
Next