I cannot use INTERSECT() between 2 columns of Lists

[Thirapon_Sinpre]

Please Help!
Hello, I am really a newbie and have a near-zero knowledge of programming language.

In each row, I have 2 columns, the first one contain a list (texts separated by comma), generated by ENUMLIST, and the another one contain a list (texts separated by comma), generated by expression “LIST(LOOKUP(“A”, “BB”, “AA”, “B”))”.
I want to use intersect() to return the values that common in these 2 list.
But How many time I’ve tried, it return blanK.

I really have no idea what to do.
Thank you.