This Excel LAMBDA gist replicates PERCENTOF functionality for other aggregates

excel-lambda-PERCENTOFFN.txt

/*
Replicating PERCENTOF for non-SUM aggregates
Usage: 
For percent of max:
=PERCENTOFFN(MAXL)(data_subset,data_all)
In GROUPBY function argument:
PERCENTOFFN(MAXL)

Note: At this time, this doesn't work:
=PERCENTOFFN(MAX)(data_subset,data_all)
In GROUPBY function argument:
PERCENTOFFN(MAX)
*/
MAXL = LAMBDA(a,MAX(a));
SUML = LAMBDA(a,SUM(a));
AVGL = LAMBDA(a,AVERAGE(a));
MINL = LAMBDA(a, MIN(a));
// etc

PERCENTOFFN = LAMBDA(function,
    LAMBDA(data_subset, data_all,
        function(data_subset) / function(data_all)
    )
);