Jetpack sharing buttons are added immediately after the post content. In some cases, you may want to insert a new element between your post content and the sharing buttons.
To control whether that element will appear before or after the Jetpack sharing buttons, you will have to change the priority of the filter. In the example below, we’ve added an author box and used the priority 18. As long as the priority is less than 19, it will appear before the sharing buttons.