You can use grouping and sorting to control the order of activities shown in the layout for TSLD and Gantt charts.
Grouping
When you choose to group activities and to show group titles, the layout depicts each group separately and identifies each group by its group title, which appears at the upper-left side of each group. You can choose to group activities by a variety of criteria, including by Project Name or Project ID, by WBS Path, and all activity codes that are assigned to any currently open project. For TSLD layouts, groupings are always sorted alphanumerically.
Sorting
Sorting determines the sequence in which activities appear in the layout. You can select a field on which to sort and then choose the sort order of ascending or descending. For example, sort by percent complete in descending order to see completed or in progress activities at the top of the layout.