Qlik Sense Pie Chart - remove dimension null value

[paola_valenti]

I'm facing a strange result in a simple pie chart.

Pie chart dimension is "Market"

Pie chart expression is sum({1<Market={x,y}>}Quantity)

Set analysis is useful because I have more than two market, but I want a focus only on this 2 (x,y).

Slices in pie are correct, but under the pie there is this warning: "This data set contains negative or zero values that cannot be shown in this chart."

In addiction, if I show chart legend, this will show ALL possible market (x,y,z,k...).

If I select x and y market manually, both warning and other markets in legend disappear, but I don't want that users have to filter themselves.

I have already checked in Community and I find out this post

Suppress zero values in Qlik Sense Pie Chart

, but the proposed solution is not applicable for me, as my dimension is not numeric.

There is any add in expression or in chart properties that can eliminate warning and unnecessary dimension value?

Thank you