Exclude whole group if value is found #2

Hi all,

I'm facing almost the same problem, as explained here, except that I want to exclude the whole group (Column Item/ group = AA/BB/ etc) if the value X (Column Code) is found.

So if we would extend the intital example:

Item	Code	Amount
AA	X	1
AA	X	2
AA	Z	3
BB	X	4
BB	Y	5
BB	Z	6
BB	X	7
CC	X	8
CC	X	9
DD      Y       1
DD      Z       2
EE      Y       3
EE      Z       4
EE      Z       5

Table1

My ask would be how to get only a "true" for group DD & EE:

Item	IsValidColumn	
AA      False
BB      False
CC      False
DD	True
EE      True

I've tried to adapt the "calculated column" example from the other thread, but it didn't worked out.

Any hint appriciated.