How to merge duplicates in a column in Ruby on Rails?

Question

I have this filter here for sign name. What I want to do is if I have more than one name of the sign to merge the content together Check the image attached. I have two serfer names. I want to display just one.

Code:

<div class="categories">
      <% @oferta.each do |o| %>
        <ul class="cat">
          <li class="pull-left"><h2><%= link_to o.offer,o %></h2><br><h4><%= o.description %></h4>
            <div class="main">
              <% if o.sigs.exists? %>
                <div id="myBtnContainer">
                  <button class="btn active"  onclick="filterSelection('o')">All</button>
                  <% for item in o.sigs %>
                    <button class="btn"  onclick="filterSelection('<%= item.name %>')"><%=  item.name%><br></button>
                  <% end %>
                </div>
                <div class="row">

                  <% for item in o.sigs %>
                    <div class="column <%= item.name %>">
                      <div class="content">
                        <%= image_tag item.image.url(), style: "width:100%"%>
                        <h4><br><%=link_to item.name,item %></h4>
                        <p><%= item.comment %></p>    
                      </div>
                    </div>
                  <% end %><br><br>
                </div>
              <% end %><br>
            </div>
          <% end %>
</div>

here is the oferta_controller.rb

class OfertaController < ApplicationController
  before_action :find_ofertum, only: [:destroy,:edit,:update,:show]
  def new
    @ofertum= Ofertum.new
  end

  def create
    @ofertum= Ofertum.new(ofertum_attributes)
    if @ofertum.save
      redirect_to oferta_path, notice: "Thank you... Your offer was created successfully."
    else
      flash.now[:error] = "Please correct the form"
      redirect_to new_ofertum_path
    end
  end
  def index
    @oferta = Ofertum.all
  end

  def show
    @ofertum = Ofertum.find(params[:id])
    @sig = @ofertum.sigs.build
  end
  private
  def ofertum_attributes
    ofertum_attributes = params.require(:ofertum).permit([:offer,:description,:sign,:place,:sig])
  end
  def find_ofertum
    @ofertum = Ofertum.find(params[:id])
  end

end

in oferta model

class Ofertum < ApplicationRecord
  has_many :sigs
end

in sig model

class Sig < ApplicationRecord
  belongs_to :ofertum
end

Answer 1

<% for item in o.sigs %>
   <button class="btn"  onclick="filterSelection('<%= item.name %>')"><%=  item.name%><br></button>
<% end %>

instead of for loop try

<% o.sigs.pluck(:name).uniq.each do |name| %>
    <button class="btn"  onclick="filterSelection('<%= name %>')"><%= name %><br>/button>
<% end %>