Create list of purchased items grouped by a parameter

Question

So I would like to create list of products that purchased by the customers as described below.

On the first table, I have a list of Purchased Order like this.

On the different sheet, I would like to make a summary of items purchased by customer A, B, C, D, F, H into a single cell for each customer, like this:

On Sheet2, I use =UNIQUE filter to get list of unique customer from Sheet1. So what formula should I use on B2 to get output like that? I've tried out some textjoin or concatenate formula with =vlookup function, but it didn't works.

Answer 1

You may try this in Cell_B2 of Sheet2:

=join(", ";filter(Sheet1!B:B;Sheet1!A:A=A2))