Add additional information in tooltip - (Column, Bar, Line, Area charts - stacked and classic)

this is very useful , for my requirement I have past month/past quarter comparisons which I would like to show in the tool tip

is it possible

1. to hide the value which is not applicable at the time for example I am changing the view with blox buttons to date granularity so ideally I only want to show month comparison when month is selected in the view 

2. The numbers are not showing in % how do I edit that please?