One of the Before & After slider widget features is the ability to create multiple Before and After sliders, display several different before & after sliders on a single widget.
To unlock this feature, navigate to the “Content” tab within the Editor and click on the "+ Add a Slider" button to create new before & after sliders.
An empty new Before and After slider will appear, where you can customize it as you wish.
For advanced customization options for multiple before & after sliders, click Here