Click the green Clone or download button and choose the Download ZIP option. Save the download to your desktop.
Navigate to the Add New Plugin WP admin page and click the Upload Plugin button.
Choose the ZIP file that you downloaded to your desktop and then click the Upload Now button.
Activate the plugin.
Finally navigate to the Connections : Settings admin page. You will find the settings under the Advanced tab at the top. Control click on each parent category that you wish to split into their own metabox.
Hope this helps, let me know.
If you have a moment, I would truly appreciate a review as they really do make a difference.
Thanks in advance for your time!