So what James94Hodges is saying is: create a new blueprint MySaveGame that inherits from SaveGame:
Add your save variables to MySaveGame, in your case an array of positions and rotations.
Then in your Create Save Game Object node, select the MySaveGame class you just created. Cast the created object to MySaveGame. Now you can modify your save variables (your positions and rotations). When you’re done, write it to disk by passing it to a Save Game to Slot node. To load the data from disk, use a Load Game from Slot node and cast to loaded object to a MySaveGame.