Yes, there's a way to do this workflow using the Knowledge app.

1. Go to the view that you wish to create a report from. Click on the gear icon and click on Insert view in article.

2. Create a new article or add the view to an existing one.

3. Click on the share button and invite your customer to the article.

4. Make sure to change their access right to read only so they won't have access to changing anything.

5. When the customer logs in to their portal view, they will have a new Knowledge button. When they click on it they will see their articles and their reports.