Table:
0
A
B
C
1
master customer id
cmi details
customer master index
2
1
Schmitt-Lang
3
2
Volkman, Mills and Ferry
4
3
Gusikowski PLC
5
4
Schmidt, Kertzmann and Lubowitz
6
5
Gottlieb, Becker and Wyman
7
6
Mayer-Hagenes
8
7
Streich-Morissette
9
8
Quigley-Paucek
10
9
Reynolds-McClure

Questions and formulas:
Question: the details from z to a and the corresponding customer master index.
Formula: SORT(UNIQUE(HSTACK(C1,B1)), 2, -1)
Formula2: SORT(UNIQUE(HSTACK(C2:C10,B2:B10)), 2, -1)
Level: medium