The following sample code demonstrates how to apply sorting to the Department and Budget columns.
Data is sorted via the TreeListColumn.SortOrder property. To avoid superfluous updates, the code is enclosed with the TreeList.BeginSort and TreeList.EndSort methods.
using DevExpress.XtraTreeList.Columns;
//...
treeList1.BeginSort();
treeList1.Columns["Department"].SortOrder = SortOrder.Ascending;
treeList1.Columns["Budget"].SortOrder = SortOrder.Descending;
treeList1.EndSort();
Imports DevExpress.XtraTreeList.Columns
' ...
TreeList1.BeginSort()
TreeList1.Columns("Department").SortOrder = SortOrder.Ascending
TreeList1.Columns("Budget").SortOrder = SortOrder.Descending
TreeList1.EndSort()