The reason you might not be able to see who shared your post on Facebook is due to the privacy settings of the person who shared it. When you click on the share option of your post, you should normally see the name of the person who shared it. However, if the person who shared your post is not in your friends list on Facebook and their privacy settings are set to “friends only,” you may not be able to see their name in the share details. In such cases, the privacy settings of the person who shared the post restrict the visibility of their name to their friends only.