A separate sales channel needs to be added in Brightpearl for each marketplace you list on for each Amazon seller account, i.e. one per seller per marketplace. This means you can report on a site-by-site basis.
For each marketplace you get to choose a price list, warehouse, sales order status, channel brand, bank account and fees account. These can be the same or different across each of your marketplaces. However, the price list selected must be the same currency as the marketplace which you are adding. This ensures that the price you see in Brightpearl is what you see on the listing on Amazon and that the order values are converted correctly.