You can enter that code into the body of the Initialize method. Make sure to keep the code that automatically appears when you select Initialize and just enter the code in the middle
Sub Initialize
Dim session As New notessession
Dim db As notesdatabase
Dim doc As notesdocument
Dim doc2 As notesdocument
Dim view As notesview
Dim noteid1 As String
Dim noteid2 As String
Dim item As notesitem
Dim collection As notesdocumentcollection
Set db=session.CurrentDatabase
Set collection=db.UnprocessedDocuments
Set doc=collection.getfirstdocument
noteid1=doc.NoteID
Forall v In db.Views
If v.isfolder Then
Set doc2=v.GetFirstDocument
While Not doc2 Is Nothing
noteid2=doc2.NoteID
If noteid1=noteid2 Then
Messagebox v.name
End If
Set doc2=v.getnextdocument(doc2)
Wend
End If
End Forall
End Sub