Forum Discussion
How to dynamically set the Parameter Current Value?
As it looks, we cannot use dynamic values in parameters right now: https://community.powerbi.com/t5/Desktop/Options-to-have-report-parameters-similar-to-what-we-have-in/td-p/27746
So the option I see for you would be to add a column to your calendar-table where only for the current day, a fixed expression/value like "Today" will be returned. You could then "hardcode" that in your parameter.
As it looks, we cannot use dynamic values in parameters right now: https://community.powerbi.com/t5/Desktop/Options-to-have-report-parameters-similar-to-what-we-have-in/td-p/27746
So the option I see for you would be to add a column to your calendar-table where only for the current day, a fixed expression/value like "Today" will be returned. You could then "hardcode" that in your parameter.