aggregating calendars

Is your feature request related to a problem? Please describe.

i would like to be able to have different groups collaborate on their own group calendars, then allow someone with access to the distinct calendars to aggregate these into a single entity to be published (read-only feed) to consumers.

as is, it is tough to decouple subscribers from collaborators to such an end.
either everyone would be collaborating on one and the same calendar, while they might not care about the other groups, or the calendars would have to be published separately, which means our organization cannot offer calendar feed consumers one over-arching feed.

Describe the solution you'd like

allow composing calendars into a feed/calendar, such that collaborators and consumers can be decoupled

Describe alternatives you've considered

having users subscribe to various calendars

Additional context

cf. similar question

Start by reviewing the requested calendar aggregation behavior and the linked similar question about aggregating multiple calendars. Define how distinct group calendars would be composed into one read-only feed while keeping collaborators separate from consumers; done means the resulting feed can be published as one overarching calendar.