At the bottom of the dashboard screen, click on the Reports icon.
You will see a list of reports. Click on the Top Report report.
By default top 5 Customers are shown. On clicking on a supplier/customer, you will see the purchases/sales respectively. On clicking on an item you will be shown the summary for the item.
Click on the filter icon on the top.
You can see a list of options. On clicking All, the all the data is shown in a sorted order.
Select the field from the list.
Now you can see the top 5 items sold in the list below.