How to match the products within the same column and the result should be matching productnumber?

[MG]

The result should look like the table given below.Need to find the matching product number within customers and the result should be the matching product number, if not null. Can you please suggest

Customer_name	Product_number	Result
Customer1	P1	P1, P2
P2
P3
P4
Customer 2	P2	P2
P5
Customer 3	P3	Null
P6

[ITWhisperer]

It is not clear how the result is derived from the customer name and product number. Please can you clarify?

[MG]

Out of the products, which are all the products that are not common across customers within a single division. How to find that, please

[ITWhisperer]

Please can you clarify your data / example?

Is product number a multivalue field for each customer?

Customer_name Product_number

Customer 1	P1 P2 P3 P4
Customer 2	P2 P5
Customer 3	P3 P6

If so, why is the result for Customer 1 not P1, P3, P4? etc.