In your code, create another string that pulls the data for the "new" filter once the button is clicked, and then join the "old" filter with the "new" filter using an AND statement.
Code:
Filter1 = "[Actual Date] BETWEEN #" & Forms![frmMyForm]![txtFrom] & "# AND #" & Forms![frmMyForm]![txtTo] & "#";
IF MyButtonClickisClicked{
Filter2 = [Actual Date] > [Promised Date]
Filter3 = Filter1 AND Filter2;
... Apply Filter3
}
Get my jist?
I don't have much vb experience. But I'm pretty sure going that route would work.