defmodule SomeModule do
   alias Phoenix.HTML

  def my_very_own_li(class, do: block ) do
        content_tag(:li, block, class: class )
  end

  def my_very_own_href(class, path) do
    content_tag(...)
    ....
  end
end

 <%= my_very_own_li("some_class") do %>
   <%= my_very_own_href("maybe_a_child_class", path, ...) %>
 <% end %>