SSRS - : How to make a conditional formatting for matrix by group?
If you are formatting cells based on group totals and not a row value, you need to use an aggregate and indicate the correct row group scope.  In this sample, &quot;UserName&quot; is the name of the row group scope on the Row Groups section of the Grouping pane
=IIf(Sum(Fields!CountFailures.Value, &quot;UserName&quot;) &gt;=1, &quot;Pink&quot;, &quot;White&quot;)