Path fields
Path fields are event's attributes names, which may use a dotted notattion
(e.g. some.field.name) to represent nested events fields.
Syntax
- Root fields are written as-in, e.g. 
fieldName - Nested fields are sperated by a dot, e.g. 
user.name,user.identity.name - Fields with spaces in their name can may be encosed in double-quotes, e.g. 
"user name","user.last name" 
Quotes matters
Enclosing a fields into single-quotes as 'some string' as a different
meaning: see literal fields
Examples
Generate fields
| make
| eval
    userid = 'jdoe',
    user.name = 'John',
    user.lastname = 'Doe',
    "user.twitter account" = "@JDoe",
    user.loc = list(1, 2, 3)
{
  "userid": "jdoe",
  "user": {
    "name": "John",
    "lastname": "Doe",
    "twitter account": "@JDoe"
  }
}