Rails, trying to avoid duplicating code (lists of URLs)

I'm trying to simplify and DRY up my rails code so as not to duplicate lists of URLs in multiple places and have to keep them in sync. I have a controller with a method parent that has instance variables for lists of urls in different categories, i.e.

def parent
  @collection1 = [
    ["Link 1", "http://link1.com"],   
    ["Link 2,  "http://link2.com"] 
  ]
  @collection2 = [
    ["Link 3", "http://link3.com"],   
    ["Link 4,  "http://link4.com"] 
  ]
end

Then in my views I have a file parent.html.erb with code

<% @collection1.each do |link| %> 
                      <a href="<%= link[1] %>" target = "_blank" class="btn btn-primary btn-block" role="button"><%= link[0] %></a>
<% @collection2.each do |link| %> 
                      <a href="<%= link[1] %>" target = "_blank" class="btn btn-primary btn-block" role="button"><%= link[0] %></a>

But I have another view, child.html.erb that I want to just display collection 1, so

<% @collection1.each do |link| %> 
                      <a href="<%= link[1] %>" target = "_blank" class="btn btn-primary btn-block" role="button"><%= link[0] %></a>

But in order to do this I have to define another method in the same controller:

def child
  @collection1 = [
    ["Link 1", "http://link1.com"],   
    ["Link 2,  "http://link2.com"] 
  ]

which is the same collection as I have in the parent method. That works but then if I want to change one the links I have to change it in both places. Please advise, I am pretty new to rails but realize this can't possibly be the way you're supposed to this! Thank you.