You can achieve the requirement to view the first 7 days of each month in dashboard by using this expression field.
Please follow the given steps to achieve this requirement:
After creating the required data source, you need to create an expression column with the corresponding date column.
Syntax: IF(DAY([DateColumn) >= 1 AND DAY([DateColumn]) <= 7 , [DateColumn], null)
Now you can bind this expression column in required widget and it will return actual value for first 7 days of a month and a Null value for all other days of a month.
You can bind this same expression column in
Filters section of a widget to exclude the
Filter(s) pop-up window through the given option and uncheck
Null value from the list like shown in the screenshot.
Now, the widget will show available data of first seven days of each month like shown in the screenshot.