Go to the Sales Module & then to Studio -> Edit menu : 

Create a new Menu (“Revenue per supplier”) based on an Existing Model "sales order line" -> Confirm -> Confirm

Then, you can : 

- Add a column to get the Supplier : Related field -> Product > Supplier

- Add a column to get the product : Existing field -> Product

- Go to the magnifying glass and add the field "supplier" that we have created (existing field) in the "group by" to be able to group by supplier

Warning: if you can't find the field you have created, you have to close and go to dashboard, debug, search for "Fields", find the one you have created and then select the "stored" and "indexed" properties. 

Then we can go back to studio, and select it in the “group by”.

You will get the revenue per product per supplier :