Hi tyeung, what type of bar chart is it?  There are a couple ways you might sort based on the type of chart.  However, it sounds like you need to specify the sort order, and you would do this in a beast mode like this:

CASE

WHEN `P&L BUCKET` = 'revenue' THEN 1

WHEN `P&L BUCKET` = 'COGS' THEN 2

WHEN `P&L BUCKET` = 'G&A' THEN 3

WHEN `P&L BUCKET` = 'depreciation & amortization' THEN 4

WHEN `P&L BUCKET` = 'other income & expenses' THEN 5

WHEN `P&L BUCKET` = 'Income taxes' THEN 6

END

Drop this is your card sorting settings area and set to ascending.  Let me know if this works for you