Filtering data in a chart/kpi

[GB41]

I am fairly new to Qlik and have been looking at creating a dashboard for the purchasing team. 

One of their requirements is to have the value of all purchased items on overdue PO lines. 

We have the fields

PartID for the items

LineTotal for the Value

OverdueFlag to mark the overdue status. 

I have created the chart which shows me the total line value per part I am just not sure how to filter this data so its only showing values from orders marked overdue. 

[Vegar · Accepted solution]

Assuming your calculation for total line per part is sum(LineTotal), and that the OverdueFlag holds the value 'True' when overdue,  then the syntax for filtering on OverdueFlag is sum({<OverdueFlag={'True'}>}LineTotal)