Creating a measure that shows the difference for the first visible date before the current date

[Flavio_Souza]

I have a simple bar chart that shows a value for each date.
I want to create a measure, to be used in the tooltip, that will show the difference in value between the last visible date in the chart.
If I'm filtering the chart so it only shows mondays, I want the tooltip for each day to show the difference from the current date to the last monday.

For instance, in scenario 1, the tooltip for 16/12 (dd/mm) will show 39.72 - 16.75 = 22.7. Notice that 16.75 is the value for the monday before.
But if I'm filtering like in scenario 2, the tooltip for 16/12 will show 39.2 - 34.9 = 4.3. Notice that 34.9 is the value for the previous day.


Scenario 1

Scenario 2

[lbendlin]

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