Hi Narayan,
Thanks for your questions about working with sliders in BoldGrid Post and Page Builder for WordPress!
I think it may be a little difficult to covert an existing block to a slider. One thing you could do is rebuild the block using one of our built in slider options. We have two options to choose from, the Section Slider and the Content Slider.
Each slide on a Section Slider can have a unique background with different page elements than the one before. With a Content Slider the background stays the same while elements like text, images, buttons, and more change on top.
You can follow this guide on working with sliders to get a better idea of how to implement the type of slider you’re looking for into your theme.
I hope this this helps! Please reach back out to us if you need any further assistance.