So, you want to pass line item details from main report to sub report?
Try these steps:
1. Right click on the sub report you have included.
2. Select option "Change Sub Report links".
3. From "Available Fields" section, select the main report database field for Line Item and move it to section "Field(s) to link to"
4. Now you can see that there will be 2 additional sections below will be enabled.
5. Link the main report field using the required field from "Report Fields" dropdown on lower right corner by selecting the checkbox for "Select data in sub report based on field:" option.
Hope this is what you are looking for.
Thanks,
Raghavendra
