You can change privacy settings on an individual post that you want to make shareable by clicking the “Privacy” icon next to the post time stamp and selecting either “Friends” or “Public.” Select “Friends” if you want friends to be able to share the post or select “Public” if you want anyone to be able to see the post.
If you want to make a previous post shareable, after locating the post, select the ellipsis icon (•••) on the right side of the post and choose “Edit Post.” Select the first drop-down menu below your name (labeled “Friends”) and choose “Public” on the new page.
Click on the Share button on the lower right corner of your post to open the dropdown menu. Choose Share to Group then select the private group you’re in. The post should be shared to the private group. Anyone else who wants to share it outside can go to the original post and share it from there.
Click on the three-dot icon to the top right of the post you want to make shareable. Then, select the Edit Audience option from the drop-down list. A list of audience options will appear. Choose Public from the list of available options to make the post shareable.
Rick’s answer: Your friends are right, Billie. Facebook no longer displays the “Share” button on posts that have their privacy levels set to “Friends”. Unfortunately, there’s no way to force the “Share” button to appear on posts that you mark as “Friends. That’s just the way it is now.