To get the list of orders that are not returned from the data set:
1. First perform inner Join on Orders + Returns to get the orders that are returned. (data set 1)
2. Perform Left Outer Join to get the details of all orders placed included returned. (data set 2)
3. Then form a calculated group with order id from table 2 whose is null and those of not null.
4. Then add the created field in the color shelf to observe difference or in the row pill. (The first order is from table 1 and 2nd order is from table 2.)
5. Now you can exclude the orders with common group ( i.e orders returned).
6. Now add other measures and dimensions to add visualizations.
Hope this helps you.