Dax command to get first data

Hi All,

I am trying to make a chart like this but I have difficulty to make a line chart.

How to create a global variable or to handle this case in DAX?
The position of the chart in current period will be impacted by the value from previous period for the whole filter context.
I am trying this calculation but I still can't get the value of opening balance in the black bar on the left.

I use all to remove the current filter but it doesn't work.
Can please someone help?

Cheers,
Susan