How to summarize data by calculating from another table?

Hi questions 

In your "Split%"table create a "week" num column based on the "start date" or "end date" as you liked.

Then create a column to merge "week", "from", "to", "sales" in  "Split%"table,

in "Actual Amount" table, create a column to merge "week", "from", "to", "sales",

Next create a relationship between "Split%"table and "Actual Amount" table based on the columns created above.

Fianlly you can create "Sales return" to "Actual Amount" table.

But i don't know which columns used to create "Total amount".

If you need more details, could you share the examples in excel file or just paste your data here?

Best Regards

Maggie