Great! Achieved after making bar distance Zero in Presentation tab.
One more thing! In expression tab, if i check 'values on data points' in first sum(sales) expression, it's giving correct. But if I check the same for 2nd TOTAL expression, it's giving three totals, though i need one. for example, in Jan month, I need 620 on top of gray bar.
In presentation tab, unchecked pop-up labels, as really there is no need for it as everything is labelled itself - month, product name, each product monthly sale, and total monthly sale; otherwise natural pop up does not look proper (especially for 2nd expression).