How do you count each same value in an array?

I have this dashboard as below.
I would like to add a column with a count value of “9”, another column with a value of “12” for each row.

I can’t find the right transformation method or option.

Thank you for your help!

try this

Thanks for you anwser but it doesn’t work, I can’t count the number of specific values.

What I’d like is to know for each line the number of 12s or 15s or any other number I have in my line.