After learning so much from the community, I would like to give back to the community something which can be useful for the beginners in set analysis understanding Identifiers $, 1 and qualifiers Total , All,
For this I have used a data set containing 20 records of employees from an excel file.
Perform some selections in the filters and observe the measure values.
I came to know the difference with "all" and "1" which you can also, just check/uncheck the property "Suppress when value is null" in the dimensions tab of chart properties and observe the values of last two measures.
one of the records is containing a null value for the field Department_id which is making the difference.