JSFiddle - React, Tailwind, and code Playground

JavaScript

var obj = {
    "email": "[email protected]",
        "societe.name": "xyz"
};

var newObj = {};
var keys = Object.keys(obj);

for (var i = 0; i < keys.length ; i++) {
    var key = keys[i];
    // you can change this to '.name' if you want to be specific
    
    if (key.indexOf('.') > -1) {
        var splitted = key.split('.');
        var innerObj = {};
        innerObj[splitted[1]] = obj[key];
        newObj[splitted[0]] = innerObj;
    } else {
        newObj[key] = obj[key];
    }
}

console.log(newObj);