rails submit with diffrent values [loop] in nested forms

Question

I am trying to deal in form with 2 level nested resource. My parrent resource is supplier. I've done adding (building) new descedants (address) in new ad edit form. I've also done adding (building) descedant of descedant (contacts) in new form but I have problem with adding descedant of descedant (contacts) in edit form. In edit form I want to add submit button [Add contact] after each contact and when user click on this button go to update method and build new contact instance in proper address -I need send with [Add contact] submit param with address ID. I have no idea how to do it. I've try hidden field but it send last hidden fiel value from loop. It is any chance to send diffrent param with submit button?

I have 2 level nested resource. Supplier has descedant -> address Address has descedant -> contact

Models: Supplier:

has_many :supplier_addresses
   has_many :addresses, :through => :supplier_addresses
   accepts_nested_attributes_for :addresses, 
                            :allow_destroy => true,
                            :reject_if     => :all_blank  

Address:

has_many :address_contacts
   has_many :contacts, :through => :address_contacts
   accepts_nested_attributes_for :contacts, 
                            :allow_destroy => true,
                            :reject_if     => :all_blank

Contact:

 has_many :address_contacts
   has_many :addresses, :through => :address_contacts

Suppliers_Controller:

 class SuppliersController < ApplicationController

   before_action :set_supplier, only: [:show, :edit, :update, :destroy]

   def index
      if params[:search]
        @suppliers = Supplier.paginate(page: params[:page], :per_page => 15).by_letter(params[:search]) 

      else
        @suppliers = Supplier.paginate(page: params[:page], :per_page => 15).order(:name)
      end
   end

  # GET /currencies/new
  def new
    @supplier = Supplier.new
    ad=@supplier.addresses.build
    ad.contacts.build
  end

  def show
  end

  def edit
    ad=@supplier.addresses.build
    ad.contacts.build
  end

   # POST /currencies
  # POST /currencies.json
  def create
    @supplier = Supplier.new(supplier_params)
    if add_address?
      @supplier.addresses.build
      respond_to do |format|
        format.html { render :new }
        format.json { render json: @supplier.errors, status: :unprocessable_entity }
      end
    elsif add_contact?
      @supplier.addresses[params[:add_id].to_i].contacts.build
      respond_to do |format|
        format.html { render :new }
        format.json { render json: @supplier.errors, status: :unprocessable_entity }
      end
    else
      respond_to do |format|
        if @supplier.save
          flash[:info] = 'Supplier was successfully created.'
          format.html { redirect_to @supplier }
          format.json { render :show, status: :created, location: @supplier }
        else
          format.html { render :new }
          format.json { render json: @supplier.errors, status: :unprocessable_entity }
        end
      end
    end
  end

  # PATCH/PUT /currencies/1
  # PATCH/PUT /currencies/1.json
  def update
    if add_address?
      @supplier.addresses.build
      respond_to do |format|
        format.html { render :edit }
        format.json { render json: @supplier.errors, status: :unprocessable_entity }
      end
    elsif add_contact?
      @supplier.addresses[params[:add_id].to_i].contacts.build
      respond_to do |format|
        format.html { render :edit }
        format.json { render json: @supplier.errors, status: :unprocessable_entity }
      end
    else
      respond_to do |format|
        if @supplier.update(supplier_params)
          flash[:info] = 'Supplier was successfully updated.'
          format.html { redirect_to supplier_url }
          format.json { render :show, status: :ok, location: @supplier }
        else
          format.html { render :edit }
          format.json { render json: @supplier.errors, status: :unprocessable_entity }
        end
      end
    end
  end

  # DELETE /currencies/1
  # DELETE /currencies/1.json
  def destroy
    @supplier.destroy
    respond_to do |format|
      flash[:info] = 'Supplier was successfully deleted.'
      format.html { redirect_to suppliers_url }
      format.json { head :no_content }
    end
  end

   private
    # Use callbacks to share common setup or constraints between actions.
    def set_supplier
      @supplier = Supplier.find(params[:id])
    end

    #for new add
    def add_address?
      params[:commit] == "Add address"
    end

    #for new add
    def add_contact?
      params[:commit] == "Add contact"
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def supplier_params
      params.require(:supplier).permit(:name, :notes, :min_order, :pay_terms, 
                                       addresses_attributes: [:id, :name, :street1, :street2, :county, :city, :country, :post_code, :_destroy,
                                       contacts_attributes:[:id, :name, :job_title, :tel_no, :fax_no, :mobile_no, :email, :invoice_email, :contact_notes, :_destroy]])
    end

end

Form:

<%= form_for(@supplier) do |f| %>

      <%= f.label :name %>
      <%= f.text_field :name %>

  <%= f.fields_for :addresses do |address| %>

    <%= address.label :street %>
    <%= address.text_field :street %>

    <%= address.fields_for :contacts do |contact| %>

    <%= contact.label :job_title %>
    <%= contact.text_field :job_title %>

    <%end%>

    <%=hidden_field_tag params[:add_id], address.index%>
    <div class="row">
      <div class="actions text-center">
        <%= f.submit  "Add contact",:class => 'btn btn-sm btn-warning custom2' %>
      </div>
    </div>

  <%end%>

  <div class="row">
      <div class="actions text-center">
        <%= f.submit "Add address",:class => 'btn btn-sm btn-warning custom2' %>
        <%= f.submit :class => 'btn btn-sm btn-success custom2' %>
      </div>
    </div>

<%end%>