display last count (of max date) in a drill down bar chart

[fareseid]

Hello,

I have the following data structure:

ID	Timestamp
1	2019-02-25
2	2019-02-25
3	2019-02-25
3	2019-02-25
4	2019-02-26
4	2019-02-26
5	2019-02-26
6	2019-02-27
7	2019-02-27
7	2019-02-27
8	2019-02-27

I need to show the last distinct count of IDs by date in a drill down bar chart.

For example when the chart shows the year, i need to show the last count of each year,

when the user clicks a specific year, i need to show the last count of each month,

and when the user clicks a specific month, I need to show the last count of each day.

By last count i mean the count where date = max(date) (for each level in the bar chart)

 Thanks.