Calculating Dynamic Balances Over a Period

Hello all,

We have a model that tracks transactions of feed. We have calculated opening & closing daily balances based on what is being received and consumed. The balances are dynamic to our slicers -  "Storage_location" and "feed_type".

I have 2 opening stock measures:

1. Opening Stock by Day: this is working perfectly, it is dynamic to the slicers "Storage_location" and "feed_type". 
2. Opening Stock for a period: If the dates are filtered to 2nd November - 6 November, this needs to show opening stock on 2nd November. This is working, however it is not dynamic to the slicers "Storage_location" and "Feed_type"

   1. Opening Stock By Day - Detail

   Please see below visualisation & DAX for the measure working perfeclty. Note - Bakateka and Barge 2 are "storage_location", the other info is "feed_type"

   Just over the days

   

   Within 1 day by "Storage_Location" by "Feed Type"  (snippet)

   

    

   DAX

   Opening Stock = VAR StorageLocation='Barge Balances'[Storage_location]

   VAR CurrentDate = 'Barge Balances'[Date]

   VAR CurrentFeedType = 'Barge Balances'[FeedType]

   RETURN

       CALCULATE(

           SUM('Barge Balances'[Daily Movement]),-

           FILTER(

               ALL('Barge Balances'),

               'Barge Balances'[Date] < CurrentDate &&

               'Barge Balances'[FeedType] = CurrentFeedType && 'Barge Balances'[Storage_location]=StorageLocation)   )

    

   2. Opening Stock for a period - Detail

    

   The below picture shows cards for details over period 2 - 6 November. You can see that the opening stock is for 2 November.  Closing Stock is calculated as [Opening Stock 2 Nov] + [Sum Receipts over the period] - [Sum Consumption Over Period]  = [Closing Stock 6 Nov].

    

   

    

   The Problem is that when I filter this for "Storage_Location" or "Feed_type",  the number just remains as the total, rather than the opening balance only for that storage location or feed type. 

    

   Current DAX

   First Day Opening Stock =

   VAR FilteredStartDate = MIN('Barge Balances'[Date])

   RETURN

       COALESCE(

           CALCULATE(

               [Barge Opening Balance],

               FILTER(

                   ALL('Barge Balances'),

                   'Barge Balances'[Date]= FilteredStartDate  )      ),  0   )

    

   Issue with this DAX

   It will not allow me to create variables for "storage_location" and "feed_Type" like in the first measure. 

    

   Can anyone please help me write DAX to calculate the opening balance over a period that is dynamic to the slicers?

    

   Thank you,

   Katie