I took a look at your file and found that Including the Null value in your ID Account filter the 1 and 2 table worksheets now match -
I think the issue you had is that the second table generated a null value when the "Email relationship" was made -
Does this help?
TableDrillDownTest JD.twbx 7.1 KB
The behaviour you're observing is due to Data Blending.
The [Id Account] filter on the TwoTables view is coming
from the Secondary datasource (Table1), so it restricts
the resulting number of Marks on a view. But it occurs
after the rows had come from the Primary datasource
to get aggregated, but before the Marks are drawn.
So when Viewing the underlying data for the particular Mark,
another query to the Primary datasource is generated,
which gives the two rows for the Category B / December Mark.
To get what you want, your could build a filter in the Primary
using the values from the linking field [Email] from the Secondary.
This could be done easily using Filter Action on a dashboard.
Please find the attached.
Hope it could help a bit.
TableDrillDownTest_YF.twbx 60.3 KB
I think Yuri is right. I actually ended up just joining the two tables instead of blending them, problem does not occur in that case.