A custom date table could be very handy in Power Bi? The build in power bi date table does not always do what is needs to do. Therefore a power query date table could be way more usefull. Download it here:

ISFILTERED
You probably know that the ISFILTERED function returns TRUE when the specified table or column is being filtered directly. But did you know that if you add multiple ISFILTEREDs together, ISFILTERED will not return true or false, but will return a number. You can combine this returned number with a switch function to influence your total levels.
