Calculate Difference between days - weeks - months

Hi Fellas,

I need some help in order to accomplish one taks in power bi.

I need to calculate the difference between two periods of time and then show it in %, but these periods are not static but dynamic. I have a graphic where I can change from days, to weeks to months.

I have calculated a measure called SUM:

Sum = CALCULATE(SUM(Consulta1[ValuetoSum]);ALLEXCEPT(Table1Table1[Day];Table1[Month];Table1[Week]))

Now, in order to calculate the difference I find myself in the trouble. I know how to compute measures in order to make the difference for days, months, etc. using the functions PreviousDay, PreviousMonth, but I don't want to make three measures (one for day, one for week and one for month). What I need is a measure that computes the difference of the previous period.

For example, I'll put this measure in a line-graphic where the Axis is Month - Week - Day. If I am in "Day" I need the measure to compute the difference with the previous day, when I change to Week (going up in the graphic) I need the measure to compute the difference with the Previous Week, etc.

So I will be very grateful if anyone can help me, thanks guys.