To unblock someone from a Facebook group, follow these steps:
Go to the group and click on the "Members" section.
Find the person you want to unblock and click on their name.
Click on the "Block or Report" button in the top right corner of the page.
Click on the "Unblock Member" button.
Click "Confirm" to unblock the person.
Keep in mind that unblocking someone will not automatically add them back to the group. If you want to add them back to the group, you will need to send them an invitation to join.
