We use the returns portal and love how easy it is for our customers. The issue is we can't export the items they are returning so that we can tie to to the RMA.
Presently Returns info lives in two reports:
Shipments->Returns. This gives the return order level info, but does not show the items being returned and their quantities.
Insights->Reports->Returned Products. This shows items returned and quantities and other line detail, but only lists the sold-to field. There is no key to link any of these returned items to their respective RMAs
The solution is to do either (or both) of these:
1) Create a Returns Detail report to accompany the Returns report, such that the Returns Detail report has the same info as found in the Insights report, but the RMA, tracking, and date info in it. Then you could easily join the two Returns reports to have all the info you need about your returns.
2) Add the RMA field to the Insights->Returned Products report, so you can pull both reports and join them.
The latter would be the easiest to do.