Retrieving parameter from relative date Slicer Power BI

I have a calculation that is being done on a weekly basis (x+y/x*40) . 40 is the number of hrs worked per week and x is the num of weeks selected.

I have a relative date slicer using which the user will select the number of weeks. The catch is that there are two kinds of relative weeks - one from the present day and one is the entire week.

If the user selects 2 weeks it will be (x+y/2*40). I have a calculation called

Tot Weeks = DATEDIFF(MIN( DimDate[Calendar Date] ), MAX( DimDate[Calendar Date]), week ) 

However, this doesn't work well if I select 'Weeks(Calendar Date)' in the drop down. For the value to be right, I created

Num weeks = DISTINCTCOUNT(DimDate[CalendarWeekOfYear])

Num weeks works fine only when 'Weeks(Calendar Date)' is selected. I am trying to retrieve the parameter passed to the slicer to get my values right.(whether the user selects 'Weeks(Calendar Date)' or 'Weeks' in the slicer).Is there a way to retrieve this or Is there a way to combine these two?