How to make filter with select all work for this case ?

[laurent_rio]

Hi,

I have table that have employee name, position, department and training hours 

Now i already create several measures 

Total Employee = DISTINCTCOUNT('Training Table'[Employee])

Training Duration = SUM('Training Table'[Training Hours])

Average Training Hours/Staff = DIVIDE('Training Table'[Training Duration],[Total Employee])

And i also want to have table with each department average training hours/staff. I make measure like this 

Department Average Duration/Staff = CALCULATE([Average Training Hours/Staff],filter(allselected('Training Table'),'Training Table'[Department]=MAX('Training Table'[Department] )))

It work when using filter with single selection 

But now i want if i select all in the filter or multiple selection in the filter, the column department average duration/staff also show constant value 
Formula still = average duration/staff = total hours/total employee and it doesnt work with DAX that i use above 

Anyone can help with the DAX ? 
I also upload the sample file for easy reference 

Training Sample 

[jdbuchanan71 · Accepted solution]

@laurent_rio 

You could also do it like this.

Department Average Duration/Staff 2 = 
IF (
    NOT ISBLANK ( [Total Employee] ),
    CALCULATE ( [Average Training Hours/Staff], ALLSELECTED ( 'Training Table' ) )
)

[Ashish_Mathur]

Hi,

This measure works

Measure = if(ISBLANK([Training Duration]),BLANK(),CALCULATE([Average Training Hours/Staff],ALLSELECTED(Department[Department]),all('Training Table'[Position])))

Hope this helps.

[amitchandak]

@laurent_rio , That means it is not using department filter in context

Try measure like

Department Average Duration/Staff = CALCULATE([Average Training Hours/Staff],filter(allselected('Training Table')))