weekly data

I would need to know more about the toggle you are describing. Is it just the week ending date? If so, you could just create a matrix with the number of tubs on site and put the week ending date in a slicer. You then shouldn't need any calculations.

If your tubs broken out on a dialy basis, then you can probably consider a calculation along the lines of

CALCULATE(FactTable[Tubulars], ALLEXCEPT(DateTable,DateTable[WeekEndingDate]))

I may need a clearer picture of what it looks like in the PBIX to understand exactly what is going on. However, one thing you can try is using variables in your measure; consider the following:

Measure = 
VAR _StartDate = SELECTEDVALUE(Job Tacker[Arrival Date])
VAR _EndDate = SELECTEDVALUE(Job Tracker[Completed Date])

RETURN
CALCULATE(
SUM(Job Tracker[Tubular Quantity]),
DATESBETWEEN(Job Tracker[Date],_StartDate,_EndDate)
)

Could you better help me understand how your data is structured? Based on how I understand it, it looks something like this:

If so, you should be able to just enter the Tubular field into the card and it should auto-sum it for you (see screenshot below).

Alternatively, you can also consider the following measure: 

TubularsAmt = 
CALCULATE(SUM(Tubular[Tubulars]),ALLEXCEPT(Tubular,Tubular[Week Ending (Calculated column)]))

Both give the same result

I would need to better understand how the data is organized to be able to provide something more helpful. What does the data table itself look like? Is there a dates column you can reference?