Which directions could I go?

I am an SEO specialist at a small agency and I am wondering what the future of my career will look like and how to progress. I was wondering, is it common for big companies to have SEO specialists or or they just a part of wider “digital marketing” roles? From, initial research it seems they exist but are not that common and thus I should be thinking about other ways that my career may progress or how I could find further opportunity in SEO.