Failed to use Drill down function when i retrieve N:N relationship chart entity

<visualization>
  <visualizationid>{81A80FF4-9710-E811-80D8-00155D006725}</visualizationid>
  <name>Campaign by Channel</name>
  <primaryentitytypecode>campaign</primaryentitytypecode>
  <datadescription>
    <datadefinition>
      <fetchcollection>
        <fetch mapping="logical" aggregate="true">
          <entity name="campaign">
            <attribute name="campaignid" alias="CountOfCampaign" aggregate="count" />
            <link-entity name="etq_etq_channel_campaign" from="campaignid" to="campaignid" link-type="inner">
              <link-entity name="etq_channel" from="etq_channelid" to="etq_channelid" link-type="inner">
                <attribute name="etq_name" alias="GroupBy" groupby="true" />
              </link-entity>
            </link-entity>
          </entity>
        </fetch>
      </fetchcollection>
      <categorycollection>
        <category alias="GroupBy">
          <measurecollection>
            <measure alias="CountOfCampaign" />
          </measurecollection>
        </category>
      </categorycollection>
    </datadefinition>
  </datadescription>
  <presentationdescription>
    <Chart Palette="None" PaletteCustomColors="91,151,213; 237,125,49; 160,116,166; 255,192,0; 68,114,196; 112,173,71; 37,94,145; 158,72,14; 117,55,125; 153,115,0; 38,68,120; 67,104,43; 124,175,221; 241,151,90; 186,144,192; 255,205,51; 105,142,208; 140,193,104; 50,125,194; 210,96,18; 150,83,159; 204,154,0; 51,90,161; 90,138,57;">
      <Series>
        <Series ChartType="Column" IsValueShownAsLabel="True" Font="{0}, 9.5px" LabelForeColor="59, 59, 59" CustomProperties="PointWidth=0.75, MaxPixelPointWidth=40"></Series>
      </Series>
      <ChartAreas>
        <ChartArea BorderColor="White" BorderDashStyle="Solid">
          <AxisY LabelAutoFitMinFontSize="8" TitleForeColor="59, 59, 59" TitleFont="{0}, 10.5px" LineColor="165, 172, 181" IntervalAutoMode="VariableCount">
            <MajorGrid LineColor="239, 242, 246" />
            <MajorTickMark LineColor="165, 172, 181" />
            <LabelStyle Font="{0}, 10.5px" ForeColor="59, 59, 59" />
          </AxisY>
          <AxisX LabelAutoFitMinFontSize="8" TitleForeColor="59, 59, 59" TitleFont="{0}, 10.5px" LineColor="165, 172, 181" IntervalAutoMode="VariableCount">
            <MajorTickMark LineColor="165, 172, 181" />
            <MajorGrid LineColor="Transparent" />
            <LabelStyle Font="{0}, 10.5px" ForeColor="59, 59, 59" />
          </AxisX>
        </ChartArea>
      </ChartAreas>
      <Titles>
        <Title Alignment="TopLeft" DockingOffset="-3" Font="{0}, 13px" ForeColor="59, 59, 59"></Title>
      </Titles>
    </Chart>
  </presentationdescription>
  <isdefault>false</isdefault>
</visualization>