Nested values copies from one object to another
Why bother with libraries? This doesn't need anything more than pure JS. Assuming the incoming data is stored in fields:

var keys = Object.keys(fields);
for(var i = 0; i &lt; keys.length; i++) {
    var key = keys[i];
    if(directory_model[key]) {
        directory_model[key].value = fields[key];
    }
}