When looking at a costs in the explorer you can drill down into specific areas to investigate your costs more closely. Clicking on a cost dimension element in the first column will refine your cost data by setting a filter to that element. When the cost table reloads, you will only see costs related to the element that you selected and the costs will be grouped by a related cost dimension. You can continue to drill down in the explorer by clicking on other elements. Eventually the cost table will show your costs grouped by resources.