Create bar chart with weeks on axis using end date and calculated start date

OK Adham , I want to make the comment that this took quite a bit of thought and work. But, I believe I have what you are looking for finally. See attached PBIX file. Had to create the estimated Start Date and then create a table like this:

Employee Weeks = 
    SELECTCOLUMNS(
        ADDCOLUMNS(
            FILTER(
                ADDCOLUMNS(
                    GENERATE(
                        DISTINCT('Table'[Employee Id]),
                        CALENDAR(MIN('Table'[Task Start Date]),MAX('Table'[Task Due Date]))
                    ),
                    "__IsWeekDay",IF(WEEKDAY([Date],3) < 5,TRUE(),FALSE())
                ),
                [__IsWeekDay] = TRUE()
            ),
            "__Work Hours",8
        ),
        "Employee Id",[Employee Id],
        "Date",[Date],
        "Work Hours",[__Work Hours]
    )

In this new table, I created these columns:

Week = WEEKNUM([Date])

Total Work Hours = 
    VAR __Table = 
        ADDCOLUMNS(
            FILTER(
                'Table',
                'Table'[Employee Id] = 'Employee Weeks'[Employee Id]
            ),
            "Must Work",IF([Date] >= [Task Start Date] && [Date] <= [Task Due Date],1,BLANK())
        )
    VAR __TotalHours = SUMX(__Table,[Must Work]) * [Work Hours]
RETURN
    IF(ISBLANK(__TotalHours),BLANK(),__TotalHours)

I created the bar chart using a categorical Y Axis to remove blank values. Two different bar visuals, one tied to a slicer and one not tied to a slicer.