On the Filters tab of Widget Editor you can add additional filters to filter widget data. For example, if your widget displays tasks data, you can filter it to display only milestones by setting up a filter TaskIsMilestone equals 1.

You can filter widget data by dates selected in the dashboard Timeline. In order to do that set tags into the Value field of a filter rule.
The following tags are supported:

• {StartDate} and {EndDate}
• {Today} and {Today±day count}
• {ThisYearStart} and {ThisYearEnd}
• {ThisQuarterStart} and {ThisQuarterEnd}
• {ThisMonthStart} and {ThisMonthEnd}
• {ThisWeekStart} and {ThisWeekEnd}
• {NextYearStart} and {NextYearEnd}
• {NextQuarterStart} and {NextQuarterEnd}
• {NextMonthStart} and {NextMonthEnd}
• {NextWeekStart} and {NextWeekEnd}
• {PreviousYearStart} and {PreviousYearEnd}
• {PreviousQuarterStart} and {PreviousQuarterEnd}
• {PreviousMonthStart} and {PreviousMonthEnd}
• {PreviousWeekStart} and {PreviousWeekEnd}

Or you can select specific time regarding the certain day. In order to do that use {Today} and {Today±day count} tags into the Value field of a filter rule. For example you can select projects created for the last three months.

If you want to filter projects by their start or finish dates, it is recommended to use ProjectSummaryTaskStartDate and ProjectSummaryTaskFinishDate instead of ProjectStartDate and ProjectFinishDate, as these dates might be out of sync with the project schedule.