Filtering values from frappe call

for my sprint doctype how can I filter the values of a particular task?
I created burn down chart .It is not working properly if one task having multiple time sheet.
From the returned value I have to filter out the time for selected task in that sprint . How is it possible please help me.
console I got like this
[Array[4], Array[1], Array[1], Array[3], Array[1], Array[3]]