Validation when add new contact

Summary:

Hi,

I have requirement like this:

I want have validation when employee adding new contact (specially spouse), so when employee adding new contact and that contact name is current active employee then the employee can't add that contact person.

Step to produce:

1. Login as employee

2. Go to Me > Quick Action > Family and Emergency Contact > Add New Contact (see the attachment SR_NEW_CONTACT.png)

Then when i input the name for the contact and that name is the current active employee, the validation is on and i can't submit the new contact.

Please help me to fullfilment this requirements.