So what i mean by nested is to add a Parent Child relation to related tickets.
An example is we get a ticket from HR advising that several new associates are being hired we then create a internal Service catalog item per new associate and related it to the original request for tracking it would be nice to show its a child ticket of the former.
It's possible that Runbooks could fix this if we could add more then one Runbook to a Incident and have them run in parallel.