i found myself …
const Query_B = context.panel.data.series.map((s) => {
const metrics = s.fields.find((f) => f.name === 'Var_en_defaut2').values;
const values = s.fields.find((f) => f.name === 'total2').values;
return values.map((d, i) => {
return { name: metrics[i], value: d };
})
})[0];
change [0] by [1]
[1] <=>index for second query (query B in my case