Clicking on a graph should change the measure value

[bathbath]

Hello,

I have this bar graph. My question is if someone clicks on the graph to say January then I want to show 1, if it is CTRL and they chose any 2 months then I want to show 2, if I don't select anything then 12 (if it is not current year) and the total number of months if it is current year. ( I am not talking about EDIT INTERACTIONS).

With slicers it's easy, but I want to show number of months when someone clicks on the graph. These are getting used in my other formulas so this number of month will become denominator in bigger formula. 

This is a return for my formula which works fine except it sums all the stores so I want to add Month measure and divide it by that based on the month selected. 

RETURN

    CALCULATE(

        sum(FACT_Store_Metrics[Store_Count_Metric]),

        USERELATIONSHIP(FACT_Store_Metrics[Date_Metric_Month_SK], DIM_Date_Rpt_P3[Date_Rpt_p3_SK]),

        KEEPFILTERS(DIM_Franchise[Franchise_SK]),

        KEEPFILTERS(DIM_Reporting_Source[Reporting_Source_SK]),

        USERELATIONSHIP(FACT_Store_Metrics[Date_Metric_Month_SK], DIM_Date_Rpt_P3[Date_Rpt_p3_SK])

    )

Please let me know if needed further clarification.

Thanks in advance.

[amitchandak · Accepted solution]

@bathbath , Your measure will filter data from the table and related table on one side. Assuming a date table is used and use filtered it will remove data

Assume you have a measure, M1. This code will show a selected range or 12 months range

new measure =
var _max = maxx(allselected(Date),Date[Date])
var _min = eomonth(_max , -12) +1
var _fil = calculate(isfiltered('Date'), allselected('Date'))
return if(_fil, [M1],
calculate( [M1], filter('Date', 'Date'[Date] <=_max && 'Date'[Date] > _min)) )