Dimension calculation based on filter date range

I am trying to calculate marketing cost depending on whether or not a customer executed a first order within the filtered date range in order to allocate the relevant marketing cost per acquisition of an order. Is there a way to reference the selected date range using some form of IF statement?

Yes, there is! There’s an thread talking about it here:

The long and the short of it is that you can use {% date_start date_filter %} and {% date_end date_filter %} in LookML to dynamically grab the range values a user enters into the date_filter.