bindig of list of objects into telerikGridView:GridViewDataColumn

Question

Good day! I have a class names Sales:

public class Sales : BaseDomain
{
        public virtual string Name { get; set; }
        ICollection<ActivityCategory> categories = new List<ActivityCategory>();
}

I bind this a List of items of this class to a RadGridView: grid.ItemSource = e.Result; where e.Result is a List. For column "Name" I make it this way: .

How can I make it for ICollection categories to show it in my RadGridView (maybe with a list of text separated by commas or with an dynamic number of chek boxes with text)?