You can use two variables , variable1 and variable2, as input boxs to take start and end time respectively. Use set analysis in the line graph to display time greater than variable1 and less than variable2.
Here is the extension of a variable.
Another option is to use a range slider to take start and end time. The logic will remain the same in the line chart.
Here is an extension of the slider object.
Thank you for your inputs. The variable methods seem to be easier to implement. I will check out the same.
However, I have another concern. When I am trying to add values to the measure fields in charts, it asks for an aggregate function like sum(), min(), max() or count(). Is there any way to add raw values to the charts and not the results of the aggregation functions. Through these charts , I want to show the change in values for particular fields based on the user selected time interval