How are leadership functions distributed in SCRUM when there is a shift from Waterfall Model to SCRUM?
typically downwards. Leadership on each level, not only C-level.
I read the Scrum Guide like this:
Controlling --> Development Team / no longer required because the short Sprints enable frequent inspection and adaptation without Controlling "from above" and without micromanagement
Process --> Scrum Master
Product Contents --> Product Owner
Other management functions might remain within management and outside the Scrum Team.
Generally 'development managers' then become chief impediment removers or points of escalation to remove impediments or make decisions. With each step up, the responsibility is there all the way to the CEO to remove impediments that are slowing the team down - as it effects productivity, speed to market and quality. I believe most CEOs care about all 3 of those! Quite often only the senior folks are able to change processes, or remove unneeded approval steps.