I'm trying to figure out which option to choose for my partner who has done 5 years of university studies in Mexico. He says he doesn't have any master's nor doctorate, and we don't think "post-secondary - no degree" would be correct... So we are trying to figure out if his university diploma and certificate are considered "bachelor's degree" or "post grad - no degree."
Bachelor's degree, assuming that his diploma is a standard university completion step. Post-secondary in Canadian parlance means after high school.
If he feels strongly that he did graduate level studies, he could put post grad/no degree. This would typically be used for
starting a post-grad degree program (after being accepted into it) and not completing it, however, not just for having more years than standard for bachelor's. (Just taking some graduate level courses for example is not what is meant)
If this is you as PR/citizen sponsoring your spouse, it doesn't much matter for the purposes of his application.