I work at a place where we have trouble finding candidates. It's hard to find a good candidate, but sometimes we find someone we really like but they don't have a lot of experience, and sometimes we find someone we really like and they're very experienced. Both can come trough the same job opening, but we'll offer them different salaries for obvious reasons. Their "level" inside the company will be different once they join.
That doesn't seem really complicated to communicate. Levels are common across large companies. Just post the targeted levels and salary bands. You can still make out of band offers if you decide the candidate doesn't meet or surpasses the intended level.
why can't those levels and corresponding salaries can be mentioned in the job post. I don't think any candidate would object and the chances of candidates rejecting your offer would be minimum.