How to: Traverse through sort columns
The following sample code uses the TreeList.GetSortColumn method and the TreeList.SortedColumnCount property to traverse through columns involved in sorting.
using DevExpress.XtraTreeList.Columns;
// ...
for(int i = 0; i < treeList1.SortedColumnCount; i++) {
TreeListColumn sortedColumn = treeList1.GetSortColumn(i);
// perform desired operations on a sorted column here
//...
}