I have multiple indices with each containing a pool of symbols. Some of these symbols will be unique to the one index and other symbols may be contained in multiple indices. The objective is separate the indices into multiple tranches(the # of tranches would be an adjustable variable) so that to minimize the # of unique symbols contained in each tranche.

So here would be an simple data set example.

# of Tranches 2

Indice Symbol
A 1
A 2
B 1
B 3
C 3
C 4
D 4
D 5


How can I automate this in excel to get Pool 1 has Indice A and B, Pool 2 has Indice C and D. I've Been pulling my hair out trying to figure this out. Much Thanks