Tablix Group Properties Dialog Box, Visibility
Select Visibility on the Tablix Group Properties dialog box to specify whether to initially show or hide the group and whether the visibility of the group can change if another report item is clicked.
When you hide a row group, you hide the group header and footer row, the group definition text (but not the column), the group instances, and any nested groups, including the default data group. When you hide a column group, you hide the column group instances.
When the report is initially run
Select an option to indicate how the report item is initially displayed in the report.
Select this option to show the report item.
Select this option to hide the report item.
Show or hide based on an expression
Select this option to vary the initial visibility using an expression.
Type an expression that evaluates to a Boolean value of True to hide the item or False to show the item. Click the Expression (fx) button to edit the expression.
Display can be toggled by this report item
Choose this option to display a toggle image that enables the user to show or hide this report item in an HTML report viewer.
Type or select the name of a text box in the report in which to display a toggle image; for example, Textbox1. The text box that you choose must be in the current or containing scope for this report item. For example, to toggle visibility of rows associated with a child group, select a text box in a row associated with the parent group. To toggle visibility of a chart, select a text box that is in the same containing scope as the chart; for example, the report body or a rectangle.