Pass Parameter from selection in Bar Chart Values

In case you can have two slicers 

https://medium.com/chandakamit/power-bi-comparing-data-across-date-ranges-36be49b68613

In case you have dates joined with fact, used in the slicers

In the same formula use userelation and crossrelation. Join two slicers with the same dates and make one of them inactive.  And turn off and on by using userelation and crossrelation.

In case you have only one time slicer and you have a relative date. Then make sure the date/time table is marked as the date table in model view.

Then try something like this

On the Fly Change % = 
Var _last_year= (max('Date'[Date Filer]))-365
Var   _This_year=year(max('Date'[Date Filer]))

Var _last_year_val= CALCULATE(sum(Sales[Sales Amount]),(Sales[Sales Date])<=_last_year)
Var   _This_year_val =CALCULATE(sum(Sales[Sales Amount]))
return
(_This_year_val-_last_year_val)/_last_year_val*100

MTD Sales Till Date = 
VAR _Cuur_start = day(CALCULATE(max('Date'[Date Filer]),ALLSELECTED('Date'[Date Filer])))
return  
calculate(sum(Sales[Sales Amount]),FILTER(Sales,day(Sales[Sales Date]) <= _Cuur_start ))