POST and GET from subdirectory

Hello guys and thanks for any help you can give me, im very new working with node and monogDB so this the first time i try to create an api. the idea is to POST element in a subroute example: api/application/:applicationID/contacts.

index.js

'use strict'

const app = require('../ticket/index.js');
const bodyParser = require('body-parser');
const applicationsCtrl = require('./applicationsCtrl');

app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());

app.get('/api/applications/:applicationid/contactsapp', applicationsCtrl.getAllContactsApp);
app.post('/api/applications/:applicationid/contactsapp', applicationsCtrl.createContactsApp);

Ctrl

function getAllContactsApp(req, res){
  Conctactsapp.find({}, (err, contactapp)=>{
    if(err){
      return res.status(500).send({message: 'Error al resalizar peticion'})
    }else if(!contactapp){
      return res.status(404).send({message: 'El producto no existe'})
    }else{
      res.status(200).send({contactapp});
    }
  });
}

function createContactsApp(req, res){
  let applicationId = req.params.applicationid;
  let contactapp = new Conctactsapp();
  contactapp.fullname = req.body.fullname;
  contactapp.avatar = req.body.avatar;
  contactapp.nickname = req.body.nickname;
  contactapp.company = req.body.company;
  contactapp.jobTitle = req.body.jobTitle;
  contactapp.email = req.body.email;
  contactapp.phone = req.body.phone;
  contactapp.sex = req.body.sex;
  contactapp.country = req.body.country;
  contactapp.channel = req.body.channel;
  contactapp.website_url = req.body.website_url;
  contactapp.linkedin_url = req.body.linkedin_url;
  contactapp.xing_url = req.body.xing_url;
  contactapp.notes = req.body.notes;
  contactapp.active = req.body.active;

  contactapp.save((err, contactappStored) =>{
    if(err){
      res.status(500).send('Error: ' + err);
    }else{
      res.status(200).send({contactapp: contactappStored});
    }
  });

}

my problem is that when i try to add a new contact that an specific application using the application id, what is does is that add the contact to all the application on the route api/applications and not to the api/application/:applicationID.

via Miguel Angel Gomez