I have no problem using reference lines to identify quartiles and selecting the data points within each quartile to review the underlying data that has been visually selected. I am curious if anyone has actual created formulas to sum the data points in each quartile and then evaluate what percentage of that total exists in each bucket. One of the data sets (either the sum of the points or the count distinct will obviously be nearish to 25% depending on what reference field was used for the reference line) which is fine. I tried writing a formula to identify the Upper and Lower Quartiles so I could sum below, above and/or within each quartile but was unable to match the formula that Tableau is natively using for the reference lines.
In short, the goal would be to create 4 groups and sum data points and count distinct in each group (quartiles). Percentages within these groups would ideally be able to be compared across multiple column dimensions in the same quartile