Private Function ChildsToSQL(oNode As Node) As String
Dim strRet As String
Dim oChild As Node
 
strRet = ""
With oNode
    If .Children > 0 Then
        Set oChild = .Child
        Do
            strRet = strRet & ChildsToSQL(oChild)
            Set oChild = oChild.Next
        Loop Until oChild Is Nothing
    Else
        strRet = strRet & " or GruppenKey = '" & oChild.Key & "' "
    End If
End With

sqlFilter = ChildsToSQL(Node)