I'm able to add Roll-Up Release Name as a data element on my reports. However, I can't filter by the same field.
If I were able to filter by the name, then that field is effectively a flag to determine whether a release rolls under another release or not.
It would also be very useful for us to be able to distinguish between a roll-up release and child release in our reports. Our team would use this for a useful drill-down view from what our executive leadership team wants to see vs one level deeper for the engineering team. As it stands, our only way of creating this view is by manually updating each individual release we want to show on a report.