Why can't I see hidden posts on Facebook?
Find your hidden posts
Once you've opened your Activity Log, tap on the Filters button, and select Categories. Open the Logged Actions and Other Activity option at the bottom of the menu. Then tap to select Hidden from Timeline, and you'll see all the posts you've hidden in reverse chronological order.
What happens to hidden posts on Facebook?
When you hide a photo or post you're tagged in on your timeline, people won't be able to see it when they visit your timeline. But the photo or post will still be visible to the audience it's shared with in other places on Facebook, such as in Feed or Search.