Display Segmented Posts Publicly
Segmented posts are only visible to a specific group of users if their user data matches the segmentation rules provided for the post. In some cases, you would need to display that segmented post inside your Public Feed, for all users, even if their user data is not matched with segmentation rules.
Now you can disable lookup for matching segmentation rules on your Public Feed. You can enable that option from Feed Settings.
If you don't want to expose all segmented posts, but only display one, you can use this tricky segmentation rule and add your own rules.