- Create a list in the orange Formulate tools of the top 10 defects. Return to green Discover, put the list in a grid (on rows say), add the articles to the rows as well. Add relevant measures. Now apply sub-totals.
- In Discover, add defects to a grid (lets say rows again), add articles as well. Add relevant measures. Open up the filter dialog (don't use quick filters). Check off the defects hierarchy only and set it up as a "Top 10" etc. Apply and add sub-totals.
Use method #1 if you plan to reuse the top 10 list across multiple reports etc. Use #2 if its more of an ad-hoc analysis.
Quick filters use the same filter engine but assume to filter ACROSS all hierarchies in the given drop zone (or axis). This makes sub-totaling a fairly useless concept in most cases.
Last, you should look at the N-of-N capabilities for your report.