I have added multiple behaviors for a KPI, but showing only one line chart. Why?

I have added multiple behaviors for a KPI, but showing only one line chart. Why?

You can see an interactive trend chart (graph) by clicking on the KPI.

Even if you add multiple behaviors to the KPI, the results are accumulated to be one result.
You cannot make two or more lines graph in one KPI.
To see the chart for other behavior, you will have to make another KPI.