Well, that happened to me aswel too many times, so I've worked out the solution and thought why not share with you lot.
It's a bit tricky but once you get hold of it then it will be very easy like no other.
OK let's start....
Go to the post that you would like see, share or bookmark. Then click on the down arrow then click on the embed like the picture below.
After clicking on the embed button, you will see embed code like the picture below.
In the embed code you will find a clear link starts with https and finishes with some numbers after posts/ and it will be between "...."
In this case our link is https://www.facebook.com/RTnews/posts/10154227202689411
After getting the link copy and paste into your address bar at the top then hit enter. That's all now you will see a single post like the picture at the top of this page.