This is probably the most advanced level a SUMPRODUCT function can reach and that is by including a nested array formula.
In our example below we want to return the 3 Largest values from the North region and sum them up. As we are asking our formula to perform multiple calculations i.e. Get the Largest 3 values or large((array,{1,2,3}), then an array formula is used. So to make this formula work we need to finish it off by pressing CTRL+SHIFT+ENTER