Группировка по подзапросу с UNION ALL для разных диапазонов дат может работать для этого.
SELECT `sales-store-id`,
SUM(GenericSales) AS TotalGenericSales,
SUM(EthicalSales) AS TotalEthicalSales,
SUM(Sales) AS TotalSales,
SUM(GenericSalesPM) AS TotalGenericSalesPM,
SUM(EthicalSalesPM) AS TotalEthicalSalesPM,
SUM(SalesPM) AS TotalSalesPM
FROM
(
SELECT `sales-store-id`,
`gen-acute-sales-after-returns` AS GenericSales,
`eth-acute-sales-after-returns` AS EthicalSales,
`sales-after-returns` AS Sales,
0.0 AS GenericSalesPM,
0.0 AS EthicalSalesPM,
0.0 AS SalesPM
FROM `sales`
WHERE `date-s` BETWEEN '2018-11-01' AND '2018-11-12'
UNION ALL
SELECT `sales-store-id`, 0, 0, 0,
`gen-acute-sales-after-returns`,
`eth-acute-sales-after-returns`,
`sales-after-returns`
FROM `sales`
WHERE `date-s` BETWEEN '2018-10-01' AND '2018-10-12'
) q
GROUP BY `sales-store-id`