The default split application sample which has item description and content in data.js file. I am editing it to jump start my project.

I want to load video instead of item header, image and content in split.html 

For example when user click a group and then selects and item it will load the video in right side. If i add "<video src=\"some-url.com\"><video>"

it works fine but is there any way to bind the video tag? so i can just load the url into that already available video tag on template of split page.

You can bind any property of any element using the data-win-bind attribute. For binding the url of a video use

<video data-win-bind="src:someProperty"/>