Without having dimensions, I don't know the way to create waterfall.
In your case, the data connection is already complicated, but I tried to make dimension from measure with union.
Then create Gantt.
This is only connection change, and you can find the file size does not change...
But may hit performance of query.
thanks for you help.
I have one question though, when you dragged the new tables 1, 2 an 3 to the union, did you create a new spreadsheet then dragged it to the union or you dragged the same spreadsheet which was already loaded in the application and then changed the name for 1, 2 and 3?
Drag same one and Tableau automatically add unique name with extra 1 , 2 and 3.
the problem with dragging the same data multiple times is that I'll have the values quadruplicated (as I have included the same table 4 times).
But for this specific Water fall, table name already specify one measure for one table with formula.
You may have more complicated logic to calculate current value, if that's the case, yes, you need to consider some more formula optimization.