As you can see in below image of facebook group post, share button is not appearing. So, the answer is your group is ‘Closed group’ or ‘Secret group’ as saved in your group settings. To get share button on every post you add, you need to change group settings to ‘Public group’.
Posts in closed groups exclude the “share” option to prevent you from sharing another member’s private information which is never appropriate to do. That said, You can share external (public) content – such as might be cross-posted from a blog or a news bureau – despite the lack of a share option.
Select “Share to a Page” if there’s a particular page you’d like to share the post to. > Select “Share on a friend’s timeline” if you want to share the post on a friend’s timeline.
First, make sure that you’re logged into your personal Facebook account. From there, navigate to the post on your page that you want to share. Click the “share” button. In the drop-down menu, select “in a group.” Then choose the group you’d like to share it with by typing the name of the group into the text field.
If no ‘Share’ button appears on a post – it is because of the Privacy Settings of the original post. If a post is set for ‘Friends Only’ (perhaps this is your Default Timeline setting) – it will not be available for ‘Sharing’ around on Facebook beyond that setting.
Make sure the first pull-down menu says Share On A Page You Manage. If it doesn’t, click on the arrow and select this option. Next, make sure the second pull-down menu directly below displays your Page (especially if you manage more than one). … Change the third pull-down menu to the right so you are Posting As yourself.
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 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.
Facebook Help Team
If you want to share a post you see on your News Feed with a single friend, you can click “Share” below the post and select “Send as Message”, which sends the post directly to your friend in a private message.
When you share someone else’s post, that post isn’t placed on your own Timeline. Instead, your share is merely a “pointer” to the original post. In other words, when you share someone’s post you’re basically telling your Facebook friends that you like that post and they should check it out.
Press the Share button as usual, but what you’re looking for is this little arrow in the bottom-right of the text box where you type in what you want to say about the link. Select that arrow to get an option selection box. From here, just select “Include Original Post”.