Yes, it is possible to programmatically duplicate the main form record, and
also the related records in the subforms, and their related records.

The example below gives you the first step. It is designed to go in the
Click event of a "duplicate" button on the main form. It adds a new record
to the RecordsetClone of the main form (an invoice in this example), and
gets the new primary key number. Then it executes an Append query statement
to add the same rows to the new record in the InvoiceDetail table. Finally,
it makes the new record current in the main form, which loads the subforms
as well.

In your case, you will also need to know the primary key value for the new
record in the subform so you can also use this in the Append query statement
for your sub-subform. If you are using Access 2000 or later, you can query
database for the @@IDENTITY of the last append. Example shown in the second
function below.

Private Sub cmdDupe_Click()
   Dim sSQL As String
   Dim db As DAO.Database
   Dim lngInvID As Long

   Set db = DBEngine(0)(0)

   If Me.Dirty Then
       Me.Dirty = False
   End If
   If Me.NewRecord Then
       MsgBox "Select the record to duplicate."
   Else
       'Duplicate the main record
       With Me.RecordsetClone
           .AddNew
               !InvoiceDate = Date
               !ClientID = Me.ClientID
               'etc for other fields
           .Update
           .Bookmark = .LastModified
           lngInvID = !InvoiceID

           'Duplicate the related records.
           If Me.fInvoiceDetail.Form.RecordsetClone.RecordCount > 0 Then
               sSQL = "INSERT INTO tInvoiceDetail ( InvoiceID, Item,
Amount ) " & _
                   "SELECT " & lngInvID & " As NewInvoiceID,
tInvoiceDetail.Item, " & _
                   "tInvoiceDetail.Amount  FROM tInvoiceDetail " & _
                   "WHERE (tInvoiceDetail.InvoiceID = " & Me.InvoiceID &
");"
               db.Execute sSQL, dbFailOnError
           End If

           'Display the duplicate.
           Me.Bookmark = .LastModified
       End With
   End If

   Set db = Nothing
End Sub

Function ShowIdentity() As Variant
   Dim db As DAO.Database
   Dim rs As DAO.Recordset

   Set db = DBEngine(0)(0)
   db.Execute "INSERT INTO MyTable ( MyField ) SELECT 'nuffin' AS Expr1;"

   Set rs = db.OpenRecordset("SELECT @@IDENTITY AS LastID;")
   ShowIdentity = rs!LastID
   rs.Close

   Set rs = Nothing
   Set db = Nothing
End Function