This is interesting to know, and your comment flipped a switch in my head - I'd like to know the organizational structure of a lot of companies out there. Is this information you acquired personally? Or is there a resource out there where you can refer to the structure of different companies?
Typically the annual report will give you an org chart with the division heads for public companies. If it isn't there it will be on the website or some other publication and if you can't find it and are an investor you can always simply ask.
From there on down it takes a bit of work to get more detail, we typically spend a day on this during the run-up to a DD to verify what we receive and use a lot of googling, linked-in, and other sources to figure out who works in the company and in what role.
The GDPR has made this a bit harder. Team pages are a good source of info for lots of companies in the 10-100 people range, they sometimes list all of their employee names + titles.
I'm not aware of a single source of truth for detailed org charts, if it exists we'd be happy to buy it, it would save us a lot of time and effort.
