Ansible playbook group variables not visible when playbook run outside the ansible root folder

How to reproduce:

jenkins@jenkins:~$ ansible-playbook ~jenkins/jobs/access-ca-portal_devel/workspace/ansible/playbooks/access.yml -i /tmp/development -f 5 --private-key ~jenkins/jobs/access-ca-portal_devel/.ssh/id_rsa -u root -v

PLAY [web-servers] ************************************************************ 

GATHERING FACTS *************************************************************** 
ok: [snf-693461.vm.okeanos.grnet.gr]

TASK: [common | Install base packages] **************************************** 
ok: [snf-693461.vm.okeanos.grnet.gr] => (item=vim,git,tar,sudo,net-tools) => {"changed": false, "item": "vim,git,tar,sudo,net-tools", "msg": "", "rc": 0, "results": ["All packages providing vim are up to date", "All packages providing git are up to date", "All packages providing tar are up to date", "All packages providing sudo are up to date", "All packages providing net-tools are up to date"]}

TASK: [common | Create application user] ************************************** 
fatal: [snf-693461.vm.okeanos.grnet.gr] => One or more undefined variables: 'application_user' is undefined

FATAL: all hosts have already failed -- aborting

Ansible version:

$ ansible-playbook --version
ansible-playbook 1.9.4

grnet / access-ca-portal

Ansible playbook group variables not visible when playbook run outside the ansible root folder #102