From version 20.0, we have introduced a new way of installing sliders.
Now, when you install a pre-built website, the slider is imported automatically.
If you wish to install only the slider from a specific pre-built website you can do that.
Proceed like you would with installing a pre-built website but when the window presented in the screenshot below pops up, select the Selected data only > Revolution Slider demo.
If you do not see this option, please make sure that revolution slider plugin is installed and active. Also, the version of your theme must be 20.0 or higher.