title: Sum rows based on values in a group
body: <p>I'm trying to sum the subtotal of one group to the value of another group. Looking at the image, sum the two highlighted values and place the sum in the circled cell. This is what I've tried,
  =iif(Instr(&quot;InpatientActivity,Observation&quot;,Fields!MetricGroup.Value)&gt;0,sum(Fields!MTD.Value),sum(Fields!MTD.Value))</p>
  <p><a href="https://i.stack.imgur.com/jcZZM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jcZZM.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/pGVCL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pGVCL.png" alt="RowGroupDetails" /></a></p>