Diff of two date fields for same period last year based on selection in date slicer

[Suryaann111]

Hi All,
Need help.
I have a date hierarchy slicer in which I can select day,year,month.
I have a calendar table which has the below structure
Calendar date date_id year month day
2018-01-01. 2018-01-01 2018 1 1

.....
2020-01-01 ....

Booking table
Rooms. Booking-start Booking_end transdte
1A. 2018-04-04. 2018-04-08 2018-04-03
1C. 2018-09-08. 2018-09-23
2018-04-23
1b. 2019-05-07. 2019-05-08
2019-05-01
2s. 2019-06-06. 2019-06-07
2019-05-05
1A 2019-03-09. 2019-03-11
2019-04-03
1C 2019-08-09. 2019-09-01
2019-04-05
This calendar date is mapped with transaction date.
When the day selected in the slicer is 2019-04-03,then the measure should calculate the diff of booking start and end dates for 2018-04-03,ie 4.
If the selection is 2019-04,then the below data is retrieved,
1A. 4
1C. 15

Someone help please

[Suryaann111]

Thanks.
This will give the selected years data.iam looking for last year measure.

[amitchandak]

datediff(booking[booking Start],booking[booking end],day)

It will give you date difference. You are already filtering using date dimension joined the transaction date. So it should filter data.

Did not get the real issue.