nested-creator

nested-creator.js

var source = {
  '1': { name: 'Linus' },
  '2.1': { name: 'Raul' },
  '2.2': { name: 'Beto' },
  '2.3': { name: 'Alex' },
  '2.4': { name: 'Josue' },
  '3': { name: 'Florian' }
};

function createObjects(parent, chainArray, value) {
    if (chainArray.length == 1) {
      parent[chainArray[0]] = value;
      return parent;
    }
    else {
      parent[chainArray[0]] = parent[chainArray[0]] || {};
      return createObjects(parent[chainArray[0]], chainArray.slice(1, chainArray.length), value);
    }
}

var keys = Object.keys(source);
var result = {};

for(var i = 0, l = keys.length; i < l; i++) {
  createObjects(result, keys[i].split('.'), source[keys[i]]);
}

console.log(result);

{ '1': { name: 'Linus' },
  '2': 
   { '1': { name: 'Raul' },
     '2': { name: 'Beto' },
     '3': { name: 'Alex' },
     '4': { name: 'Josue' } },
  '3': { name: 'Florian' } }