Hi Massimo,
You need to use/update a data module. In your data module, you should be able to create a calculation, for instance:

Then you will be able to filter using this new calculation.
Regarding the current date, you will need to add relative date analysis in your data module. Then you will be able to select your current date before starting your dashboard.
Best regards,
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Patrick Neveu
Collaboration Betters The World (CBTW)
IBM Champion
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