The query below will return all price levels for which the item has a set price. It does not include price levels for which the item doesn’t have a price specified.
SELECT BUILTIN.DF( Pricing.PriceLevel ) AS PriceLevelName, Pricing.PriceQty, Pricing.UnitPrice FROM Pricing WHERE ( Pricing.Item = 1223 ) ORDER BY PriceLevelName, Pricing.PriceQty