I was unable to see the Blueprint_splines Content Example at first also. What I had to was delete the past Content Examples in my library and then re-download the Content Examples from the Marketplace. When this is complete, start up the Content Examples. When the Content Example level loads, click on the Open Level in the file tab on the top tab in the editor. You should see the Blueprint_Splines example from that list.
Let me know if this fixes this issue. Thanks and have a great day!