Roll up multiple group calendars on SharePoint page

I have a requirement to make a corporate calendar on a M365 environment. I have all options available to me, however I am finding all options have pros and cons and none of the are a full solution, so I was wondering what the community thoughts are?

What I need:

A corporate calendar fed by 4 office calendars

Or

1 corporate calendar where I can filter events on office pages. (Tag event for HR and only HR events show on HR’s page)