Date in this lesson don't have in the data set at the last lesson!

I confirm that you don't have the Date field, but you can create a calculated field:

DATE(STR([Year])+"-"+STR([Month])+"-01")

how should i use it do i create the date field and follow along with the video or what !! , i did so and when i try to check the true box after adding the date range to the filter  i simply find only the false one and it doesn't work  so what now ?

This is a calculated field, which you can create from the Analysis tab. At this point in the course, I'm sure you know how to do it. :)

The value true is found when creating the filter in the general tab "Select from list". You can also edit an existing filter to check the correct value.

Please how did you arrive at this formula

DATE(STR([Year])+"-"+STR([Month])+"-01")

Also, Is there any other simpler approach to arrive at the same output for the Date Field.

Also i did not find a True Box

The formula can be described as follows:
DATE() will make the input into a date data type
The inputs have to be a string format for the calculation to work (if you add month(03) and year(2009), you would get 2012 which isn't what we want), STR = string, which is a technical term for text data
The +"-"+ simply represents the delimiter between the numerical values in a date 01-01-2000
The user above used "-01" to represent the first day of the month as described in the excel dashboard videos. You can use any day but we just happened to pick 1 for consistency sake.