I don't think Tableau groups aggregates so I'm looking for a workaround...

I am working with Student Test Scores attempting to find the percentage of students in each Score Band (group) based on the students Max English Score.  The Scoring Bands are not evenly distibuted (explained below).

I can pull the students Max English Score - no problem

//Regents ELA

IF IsNull(Contains([Test_name],"Regents ELA")) then 0 //No Assessments

else IF Contains([Test_name],"Regents ELA") then [scaleScore] //ELA Assessment

end end

//Max([Regents ELA])

Max([Regents ELA])

The problem comes when I place the student's Max([Regents ELA]) score into in Group.  The data group first then Max.

These are my groups.

<55

55-64

65-74

75-84

>=85

Most students only have one Regents ELA score and the grouping works fine for them.  It is the student who has more than one score and a score that cross groupings that I am struggling with.  For example, a student who took the Regents ELA test twice and scored a 54 and a 58, show in both the <55 and the 55-64 groupings.  I want them to only show in the 55-64 grouping so I can show the % of students in each group.

To sum it up (no pun intended) I want to Max then Group and Tableau wants to Group then Max.  So far, Tableau is winning.