pg_search.rb

class Candidate < ActiveRecord::Base
  include PgSearch
  pg_search_scope :search_by_candidate,
    against: {
      enterprise: 'A',
      last_name: 'B',
      first_name: 'C'
    },
    using: {
      tsearch: {
        prefix: true
      }
    }
end
Candidate.create!(enterprise: 'Brand And Celebrities', last_name: 'Bordage', first_name: 'Quentin')
results = Candidate.search_by_candiate("Brand") # [Brand And Celebrities]