The field of OHS/SHE safety, whatever you want to call it doesn't have set in stone definitions/roles for its tiers. Te titles and meanings can range wildly. For example, responsibilities and experience ranges for a "Junior OHS Advisor" can range from company to company. Some use under 3-5 years and at some companies, it's under 1 year of experience. Also, the level of education required is a very fuzzy area to the profession. The words "Advisor" and "Officer" are also not well defined nor well understood in the workforce of frontline workers.
This from personal experience: unless you know an HR person or manager of a big company, don't take OHS as your first education. Go into it after years of experience in a field. There aren't well defined education requirements for OHS personnel.