Seperate items from column B with komma based on items form column A

Question

Hello in excel i have this tabel:

Column 1	Column 2
A	A1
A	A2
B	B1
B	B2

How do I get it to look like this:

Column 1	Column 2
A	A1, A2
B	B1, B2

So I want the unique items from column A and the items that belong to them from Column B seperated by a komma.

Answer 1

You may try the following formula-

=LET(
x,UNIQUE(A2:A5),
y,BYROW(x,LAMBDA(l,TEXTJOIN(", ",1,FILTER(B2:B5,A2:A5=l)))),
HSTACK(x,y))