Sort Attribute Collection Editor (Model Designer)
Select the fields by which you want Report Builder users to be able to sort multiple instances of this entity by default.
Lists the attributes that you have added in the order that they should be displayed. You can change the order of the fields by clicking the Up or Down arrow buttons to the right of the list box.
Click the Add button to launch the Select Sort Attributes dialog box and select the attributes that you want to add to this entity.
Click the Remove button to remove the selected attribute from the Members list.
The Properties list box displays the AttributeName and SortDirection properties of each member of the list box. To set the sort direction for each field, click the SortDirection arrow and select Ascending or Descending. By default, Ascending is selected.