How to create customize view for rails admin?

config.model Utility do
  configure :preview do
    pretty_value do
      util = bindings[:object]
      %{<div class="blah">
        #{util.name} #{util.phone} #{util.logo}
      </div >}
    end
    children_fields [:name, :phone, :logo] # will be used for searching/filtering, first field will be used for sorting
    read_only true # won't be editable in forms (alternatively, hide it in edit section)
  end

  list do
    field :code
    field :priority
    field :preview
  end

  show do
    field :code
    field :priority
    field :preview
  end

  # other sections will show all fields
end

With simple configuration just add a rails_admin block and write a class method to your model then call that method.

app/models/demo.rb
rails_admin do 
  def self.full_name
    "#{first_name} #{last_name}"
  end
end

Now call this method it will return full_name as for example.