Occupation graph
O*NET records every occupation's tasks, and maps every task onto a shared library of detailed work activities. Because that library is shared, two jobs that look unrelated on an org chart can turn out to do largely the same work — which is what makes the redeployment question answerable.
Tasks rolled up to O*NET's 41 generalised work activities.
Ranked by overlap of detailed work activities, not job title.
The shortest chain of occupations that genuinely share work — a rough map of where people could move.