Bar offset when value from previous expression is null
I am trying to create a bar chart in which the bar height of second expression should start from the ending of bar from expression one and so on. In bar offset of second expression I have provided first expression and it works fine and I see that the bars are placed properly. But the problem is, when the expression value of first expression is null, then I do not see second expression bar. I only see the value of it. How can I write an expression in bar offset option to see the second bar even when the first expression value turns out to be null (or doesn't have any entry in that field)?
Re: Bar offset when value from previous expression is null
Yes, that is what I wanted. But there is a small difference that I see here. In the attached image, third bar has to start from where the second bar ends. But I see that it starts from x-axis line. Is it possible to manipulate the expression and make the third bar start from the point where second bar ends?
Or is it possible to create the bars in below format?