This was a pretty confusing achievement to try to get because the description is… not very clear on what it’s referring to. I spent a lot of time mindlessly making my equids jump over all the hurdles with no luck.
So, what does it specifically want you to do?
You will want the Steeple Chase structure first, make sure you have placed the hurdles, hedge and wall (Stones). Have your animals jump over all of these.
You will then delete the Steeple Chase structure, keep your hammer tool out, and change one of the hay piles to a small hedge.
Have your animals jump over this hedge as normal, and you should get the achievement!