It's difficult to define a specific job, given the many practices you learn through ITIL can be applied to most aspects of many job roles - in my opinion that is why most job descriptions within industry usually put ITIL as a 'desired' certification.
If you start with ITIL4 Foundation, you'll touch on the basics of:
Incident Management
Problem Management
Service Request Management
Change Enablement
...plus many many more.
Whilst having your ITIL certification won't guarantee you a job as a Change Manager, Problem Manager or HPI Manager, it's the first steps to understanding the principles of each practice which you can apply over time to roles. ITIL is a set of guiding principles which you can apply as necessary to what you're doing, within IT and beyond...
For example: I'm the Operations Lead for a small team within a global organisation. I am certified in ITIL v3 and ITIL4 Foundation, and have a few of the intermediate ITIL v3 certifications too (Service Ops, CSI etc). I wouldn't say I use what I've learnt everyday, but when on-boarding new services you take the ITIL practices into account to ensure all elements of IT service management are covered. I also head up a Support team, who support Atlassian products for 1,000's of users - so it's important for us to have processes in place for Incidents, Problems, Change and Service Requests (we also added Risk - although not a defined ITIL process). Jira Service Desk is ITIL certified out of the box for Incident Management, Problem Management, Change Management and Request Fulfillment - so if you're looking for an ITIL compliant product for these aspects, start with JSD 😃 (https://www.atlassian.com/blog/jira-service-desk/jira-service-desk-itil-certified)
