Displaying various form create on a page

company.html.erb

<section class="row-doubles">
	<div>
		<div class="title">Add Department</div>
		<div class="content pad10">
			<%= form_for @department, url: 'department_path' do |f| %>
			<p>
				<%= f.label :name, 'Department Name' %>
				<%= f.text_field :name %>
			</p>
			<p>
				<%= f.label :parent %>
				<% department_array = @departments.all.map { |department| [department.name, department.id + 1] } %>
				<%= f.select :parent, options_for_select([['no parent', 1]] + department_array) %>
			</p>
			<%= f.submit 'Add Department', class: 'btn-std' %>
			<% end %>
		</div>
	</div>
	<div>stuff</div>
</section>

dashboard_controller.rb

class DashboardController < ApplicationController
  before_action :require_login
  before_filter :init

  def index
    @departments.each do |department|
      childfetch = Department.where(parent: "#{department.name}").select('name')
      instance_variable_set("@#{department.name}Children".gsub(' ','_'), childfetch.map { |child| "#{child.name}" }.join(',') )
    end
  end
  def office

  end
  def preferences

  end
  def company
    @department = Department.new
  end

  private

  def require_login
    unless session[:user_id].present?
      redirect_to root_url
    end
  end
  def init
    @departments = Department.where(parent: '')
  end
end

department_controller.rb

class DepartmentController < ApplicationController
  def index
  end
  def create
  	@department = Department.new(params[:department])
  end
  def edit
  end
  def update
  end
  def destroy
  end
end

error.txt

No route matches [POST] "/dashboard/department_path"

(The `new` page for department creation is in dashboard/company as shown in the routes.rb)

routes.rb

Rails.application.routes.draw do
  get 'department/index'

  get 'sessions/new'

  get 'users/new'
  get 'login' => 'sessions#new', as: :log_in
  get 'logout' => 'sessions#destroy', as: :log_out
  resources :sessions, :users, :staffs, :departments
  get 'dashboard/user' => 'dashboard#user', as: :dashboard_user
  get 'dashboard/company' => 'dashboard#company', as: :dashboard_company
  get 'dashboard/preferences' => 'dashboard#preferences', as: :dashboard_setting
  get 'dashboard/office' => 'dashboard#office', as: :dashboard_office
  get 'dashboard' => 'dashboard#index', as: :dashboard
  get 'login' => 'welcome#login'

  root 'sessions#new'
end