4 Replies Latest reply on Nov 24, 2016 3:53 AM by Marie-claire Fournier

    Filter & Calculations on blended data

    Marie-claire Fournier



      I've been struggling with this one for a few days now.


      In summary :

      I have 2 data sources containing the same data but being filtered for different periods.

      Filters are applied at context level as I'm using LOD calculations.

      Same KPI are calculated in both data sources. I'm struggling to calculate the difference between the KPIs of the 2 periods as they get affected by filters.


      In illustrated details :

      Data source

      Requirement :

      End user can select the current period

      Requirement :

      KPI calculation for

      - current period

      - previous period

      - difference between current and previous

      This is where it all goes wrong

      Data structure

      (maybe this is not the best approach,

      I'm open to suggestions)

      - 2 extracts of the same data

      - filtered by boolean : selection date

      Problem : Filter All using related data

      on blended data


      Is there a way to have the criteria 1 filter

      acting on both data source independently ?

      Reason why date selection is a filter

      set up at context level and why I use 2

      data sources


      This is because of the KPI :

      % of Suppliers in 80% of Spend Previous Period


      I'm documenting it, in case someone wants to

      steal the idea.

      Also, the next step will be to calculate the

      difference between these 2 KPIs.

      Calculations :




      Worksheet :

      table calculations to be done at vendor level

      sort the vendor by descending order by "1 Spend by Suppliers"


      I am attaching both excel data source and the packaged tableau file. Hopefully, my explanations are clear enough. I found it difficult to explain simply a complex problem.


      I would be grateful if anyone could help me with this calculation issue.


      Thanks very much