Remap Object by .

JavaScript

function remapObject(original){
    var result = {};
    Object.keys(original).forEach(function(key) {
        function splitNode(node, nodes){
            var name = nodes.shift()
            node[name] = (nodes.length >= 1)
                ? splitNode(node[name] || {}, nodes)
                : original[key];
            return node;
        }
        splitNode(result, key.split("."));
    });
    return result;
}

var original = {
        "id": 123,
        "child.id": 456,
        "child.other": 678
    },
    result = remapObject(original)
    
console.log(original);
console.log(result);