Applying a rule to blanks

[nostradukemas]

I have the below files that are joined on SubAdvisorID.

I'm working on a clustered bar chart that shows the Inflow (Inflow_Outflow) by Firm (Sub_Advisor_Key). However, not every entry on the Inflow_Outflow sheet has an associated Firm - which leaves "Blank" as my second largest firm.

Is it possible to create a rule that if a row on Inflow_Outflow doesn't have an associated Firm, I can choose a different field for it to group into - ModelName, for example - instead of just rolling up as Blank?

[Cmcmahan]

You'll likely need a calculated column for this.  IIRC, you can't cluster by the result of a measure.  If you can group by a measure instead of a column, then you can use SELECTEDVALUE instead of RELATED. 

ClusterGroup = IF( RELATED([Firm]) <> BLANK(), RELATED([Firm]), [ModelName])