I doesn't make sense.
Which price and date will appear for these ones? Difference first less second?
It's easy to build but hard to mix with fruitname.
Follow an example in separated sheets.
Fruitname spread.twbx 25.2 KB
What you want to do is creating two measures along the lines of:
if parameter_fruit1 = apple
then sum(if fruit = apple then price else null end)
if parameter_fruit1 = banana
then sum(if fruit = banana then price else null end)
Create the second one bases on parameter_fruit2.
Create a third one where you basically just subtract the previously created calculated fields from each other.
Drag the date dimension onto the rows shelve and drag out the third calculated field (diff) and that should do the trick.