Select Filter on the Gauge Properties dialog box to define filtering options for the gauge. Filters work the same way for gauges as they do for charts. The dataset is filtered in the report, which affects the order of items in the dataset. This is important because the gauge only shows the first value of your dataset.
Type or choose the expression to which you want to apply a filter. Click the Expression (fx) button to edit the expression.
Choose the data type for Value. When possible, choose a data type that matches the data type for Expression.
The values in Expression and Value must evaluate to the same data type. For example, if Expression is set to a field that has the data type System.Int32 and Value is set to 7, from the drop-down list, choose Integer.