I have a problem here. I need to filter people search results to only return a certain group of users from search based on their job titles. Let's say your job title is Cleaner or something instead of developer or manager or even Executive for that matter, the search results show return nothing. But if you're a developer, manager or Executive people search should return you're profile.
Your question says Sync, but you are asking about search. (You can prevent them from showing in the User Profile Sync.) For Search you can modify the default People Result Source. Change it by adding an additional exclusion for