Вы можете сделать что-то вроде:
let result = json.Results.series.map((serie) =>
serie.data.map(({ year, periodName, value }) => ({
year,
periodName,
value,
}))
);
let json = {
status: "REQUEST_SUCCEEDED",
responseTime: 214,
message: [],
Results: {
series: [{
seriesID: "CES0000000001",
data: [{
year: "2020",
period: "M03",
periodName: "March",
latest: "true",
value: "151786",
footnotes: [{
code: "P",
text: "preliminary",
}, ],
},
{
year: "2020",
period: "M02",
periodName: "February",
value: "152487",
footnotes: [{
code: "P",
text: "preliminary",
}, ],
},
{
year: "2020",
period: "M01",
periodName: "January",
value: "152212",
footnotes: [{}],
},
{
year: "2019",
period: "M12",
periodName: "December",
value: "151998",
footnotes: [{}],
},
{
year: "2019",
period: "M11",
periodName: "November",
value: "151814",
footnotes: [{}],
},
{
year: "2019",
period: "M10",
periodName: "October",
value: "151553",
footnotes: [{}],
},
{
year: "2019",
period: "M09",
periodName: "September",
value: "151368",
footnotes: [{}],
},
{
year: "2019",
period: "M08",
periodName: "August",
value: "151160",
footnotes: [{}],
},
{
year: "2019",
period: "M07",
periodName: "July",
value: "150953",
footnotes: [{}],
},
{
year: "2019",
period: "M06",
periodName: "June",
value: "150759",
footnotes: [{}],
},
{
year: "2019",
period: "M05",
periodName: "May",
value: "150577",
footnotes: [{}],
},
{
year: "2019",
period: "M04",
periodName: "April",
value: "150492",
footnotes: [{}],
},
{
year: "2019",
period: "M03",
periodName: "March",
value: "150282",
footnotes: [{}],
},
{
year: "2019",
period: "M02",
periodName: "February",
value: "150135",
footnotes: [{}],
},
{
year: "2019",
period: "M01",
periodName: "January",
value: "150134",
footnotes: [{}],
},
{
year: "2018",
period: "M12",
periodName: "December",
value: "149865",
footnotes: [{}],
},
{
year: "2018",
period: "M11",
periodName: "November",
value: "149683",
footnotes: [{}],
},
{
year: "2018",
period: "M10",
periodName: "October",
value: "149549",
footnotes: [{}],
},
{
year: "2018",
period: "M09",
periodName: "September",
value: "149348",
footnotes: [{}],
},
{
year: "2018",
period: "M08",
periodName: "August",
value: "149268",
footnotes: [{}],
},
{
year: "2018",
period: "M07",
periodName: "July",
value: "149024",
footnotes: [{}],
},
{
year: "2018",
period: "M06",
periodName: "June",
value: "148888",
footnotes: [{}],
},
{
year: "2018",
period: "M05",
periodName: "May",
value: "148669",
footnotes: [{}],
},
{
year: "2018",
period: "M04",
periodName: "April",
value: "148391",
footnotes: [{}],
},
{
year: "2018",
period: "M03",
periodName: "March",
value: "148254",
footnotes: [{}],
},
{
year: "2018",
period: "M02",
periodName: "February",
value: "148078",
footnotes: [{}],
},
{
year: "2018",
period: "M01",
periodName: "January",
value: "147672",
footnotes: [{}],
},
],
}, ],
},
};
let result = json.Results.series.map((serie) =>
serie.data.map(({
year,
periodName,
value
}) => ({
year,
periodName,
value,
}))
);
console.log(result);