NOTE: This suggestion is for JIRA Portfolio Server. Using JIRA Portfolio Cloud? See the corresponding suggestion.
Relates to JPO-1218 and JPO-83
A 'plan-of-plans' view should be available that pulls together scheduling information from multiple plans, possibly as a read-only report.
This would be invaluable not only to view dependencies between plans (see JPO-1218 and JPO-83) but also to view and compare higher-level shared information between the plans e.g. if teams share releases and initiatives.