What does someone in Public Administration, Resource and Environmental Studies, Business & Social Sciences specialize in?

Public administration, resource and environmental studies, and business and social sciences are three separate courses of study. It is very unlikely that anyone would pursue all three, and anyone who did pursue all three would—by definition—be a generalist rather than a specialist (since a specialist is someone with a particular focus). Whether they had a small amount of knowledge or a large amount of knowledge in any one of those areas would depend on how much they had studied each one.

That said, someone might have knowledge that enables them to teach in all three departments even if they only specialize in one of them. Such a person might be referred to as a professor in the departments of public administration, resource and environmental studies, and business and social sciences departments, and might even be referred to as a professor of public administration, resource and environmental studies, and business and social sciences. But that would make their title a description of their job rather than a description of their specialty.

Agree with @SavoirFaire. They probably have some narrow experience within the overlap of the three departments and have teaching/research appointments in each. Environmental studies is typically interdisciplinary, with content from business, public administration, and social sciences. Their specialty, perhaps, would be something within environmental studies, while they hold joint teaching and/or research appointments in each of the departments.

I just don’t get it. Too vague for me. I still don’t know what exactly to go this professor to instead of the other ones. Anything can be related to the environment, space for example, and just about anything else.

…And social sciences includes:
” The disciplines include, but are not limited to: anthropology, archaeology, communication studies, economics, history, musicology, human geography, jurisprudence, linguistics, political science, psychology, public health, and sociology.” so which one did he/she study, since it can’t be all, right?

Link for the above, https://en.wikipedia.org/wiki/Social_science

Sounds to me like those are the academic departments the prof works under, not their specialty.

It could be alzheimers.