With 10 rows for page 1 and 3 rows for page 2 I would create a new DW (dw2), copy the DWO from your current dw (dw1), share the data between the two DWs, fileter each DW f=so dw1 shows only page 1 and dw2 shows only page 2, and display them either side by side or dw1 on top of dw2.
If you MUST have a button to switch between them, then:
1. Add a computed field or a computed column to specify on which PAGE that the current row of data exists.
2. Default to page one on the RetrieveEnd event and filter the DWO to display page 1
3. ADd your button to the window that toggles between Page 1 and Page 2.
- when the button is clicked, filter the DWO accordingly.