Teaching in Training centers, you do have some opportunities to advance higher up or gain diverse work experience, depending on which company it is.

You could get bumped up to Academic Director, Senior Teacher or a Teacher Trainer. Sometimes this allow you to work with HR and get involved with the hiring process. These companies sometimes offer positions in marketing for their ESL company if you possess any additional skills they can use. Sometimes they have job offers to do work as curriculum developer or editor for their teaching materials.

But as far as public schools and international schools. It's just work as a teacher with potential pay increase yearly. Maybe at most you could get promoted as a lead teacher at the school.