Basically, in the Creating a Scene Selection UI tutorial, they show how to add one scene to another without destroying anything in either scene by using Application.LoadLevelAdditive.
However, this is now deprecated and the Unity Editor says to use SceneManager.LoadScene instead.
My problem, as a Unity newbie, is how do I use SceneManager.LoadScene to do what Application.LoadLevelAdditive did? What I currently have is a menu screen in one scene and I want to make a second scene with just a bubble particle effect and combine the two so that when the player clicks on a hidden button on the menu screen, the bubbles appear on the side of the menu screen.
Thanks in advance for any help with this.