How to get return url in asp.net core

I need return url during login and need to redirect to the same path. I am authorizing user using ActionFilterAttribute like below method

 public class AuthorizationAttribute : ActionFilterAttribute
 {
        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
        }
 }

and need that last url(return url) in class file. If anybody have any idea please share it.

I have got some idea from 

http://stackoverflow.com/questions/38772394/how-can-i-get-url-referrer-in-asp-net-core-mvc

but it's not working in class file.

Thanks