Can someone who blocked you see your posts in a group ?

[Loreen]

If the person blocked you, you would not be able to "check" on that person because he or she would be invisible to you.

Likewise, YOU are invisible to that person, so anything you post will not be seen regardless of where you post it.

More likely, that person didn't block you, but put you on his restricted list, or just make the account private.

Instead of simply checking for his name every day and wasting your time with that, block him. That way you will know that he can't see your stuff.