node.tag will not pass to my DeptList private function. Node.tag will get the information, but just will not send it.

Error highlighted in yellow ^^ Private Function DeptList(intID As Integer) As String
Error highlighted in grey ^^ .movenext
========================================

Private Sub tvwOffices_NodeClick(ByVal Node As Node)
    
    If Node.Tag <> "" Then
        txtDeptList.Text = DeptList(Node.Tag)
    Else
        txtDeptList.Text = ""
    End If

End Sub
----------------------------------------
Private Function DeptList(intID As Integer) As String

Dim strSql As String, str As String, strMsg2

strSql = "Select * from tblEmployees where fldDepartmentID = " & intID

adcEmp.RecordSource = strSql
adcEmp.Refresh

Do

   str = str & adcEmp.Recordset("fldName") & adcEmp.Recordset("fldPhone") & vbNewLine
   adcEmp.MoveNext

Loop Until adcEmp.Recordset.EOF

txtDeptList.Text = str

End Function

Offhand, you should:
1) convert the tag to an integer
2) test to make sure your not at the BOF/EOF of the recordset before storing the values into a string variable

Although there are numerous (potential) problems...

Is adcEmp a control? If so you shouldn't be using it the way you are, unless you need results displayed.
If it's a variable for a connection, you can't do what you're trying to do.

For:
txtDeptList.Text = DeptList(Node.Tag)
it will set the return value to the result, given your code it will ALWAYS be ""

For:
txtDeptList.Text = str
in the function, it should be:
DeptList=str