I have ONLY one and under that we have group of
- 1
-
- 2
-
You cannot convert a single list (containing more than 2 items) into 2 columns via the display: table properties because you need some element to act as the table-row. Without an element acting as a table-row, all adjacent elements that are set to display: table-cell will be contained within an anonymous table-row element that cannot be modified or styled in any way.
Your only option is to either change the markup (to use tables or lists of lists) or use a different approach to your CSS: either floats/inline-block on the lis or using the columns property on the ul.