Write your Sales Condition calculation like this:
if [Order Date]>= [Date start]
and [Order Date]<= [Date end]
then [Sales] END
You originally specified a SUM([Sales]) in your calculation but this is not necessary since it's automatically a SUM when you use the measure.
Hope this helps!
Matthias is on point! ATTR and SUM are aggregation functions in Tableau, that means they will get a result out of a combination of rows. In your case, you want to limit the rows before they get aggregated (i.e. only look at the transactions between the Start and End Dates, then get the SUM of Sales). This is what Matthias wrote, a row-level formula, which returns one result for every row.
Thanks for support. I have to sum(sales) because I blending 2 data source, calculation Sum(Measure). So that I don't know how to sum Sales with conditional Order Date < Date( create by paramter)