Create Measure to show total sales based on the selected date's currency exchange rates

[analytics-ecoma]

Hello, 
I am trying to create a measure which gives me the sales of by converting into user's choice of currency (USD/GBP). eg :  Sales for the period January 1 - January15  should return me the total sales by converting into USD from EUR, i.e Jan1 total sales should be converted to USD using that day's exchange rate and so on.

Below are the columns of the currency exchange table (Screenshot attached)

• Date
• To_currency : EUR is the base currency here
• From_currency : Multiple currencies
• value : exchange rate of the day.
  
  I have come up with the below formulae which works good after applying date filter which only takes last 2 days exchange rate. I know it is not ideal solution.
  I am struggling to calculate sales with that day's currency excahnge rate. Help me out
  
  
  Sales conversion for Total Sales =

  IF(SELECTEDVALUE(curency_exchange[to_currency_code]) = "USD", FORMAT([Total Sales]* SELECTEDVALUE(curency_exchange[value]), "$0,00"),

  IF(SELECTEDVALUE(curency_exchange[to_currency_code]) = "GBP", FORMAT([Total Sales]* SELECTEDVALUE(curency_exchange[value]), "£0,00")))