To enable a user to change the sort order of report data, add interactive sort buttons to columns. Users can toggle a table to sort between ascending and descending based on the column value. Interactive sort is supported in rendering formats that allow user interaction, such as HTML.
You add interactive sort buttons to a text box. By default, every Tablix data region cell contains a text box. In the text box properties, you specify which part of a table or matrix data region to sort (the parent group values, the child group values, or the detail rows), what to sort by, and whether to apply the sort expression to other report items that have a peer relationship. For example, if a table and a chart that provide views on the same dataset are contained in a rectangle, they are peer data regions. When a user toggles the sort order in the table, the sort order for the chart also toggles. For more information, see Adding Interactive Sort to a Data Region.
For step-by-step instructions, see How to: Add Interactive Sort to a Table or Matrix (Reporting Services).