How can I hide whole chart line, when one of the expressions value is zero?

[#1]

Dear Community,

I'm stuck on this problem, and I guess that there is a simple way to solve it.

I need to hide a line from a chart if a certain expression is zero (or null), even if other expression value is different from zero.

I attached a dummy example.

Regards
Leonardo

[#2 · Accepted solution]

I found a way, simple but works. Just use an 'if' in the second expression.