You can use the render function in a view. You can create a shared view (name it whatever, SharedView, FormHelpersView, etc) and move the rendering there.

# in the template, form.html.eex
render MyApp.SharedView, "radio_group.html", form: f, data: @data, field: :field %>

2 options for the shared view template. Return the html from the view’s render function or create a template.

defmodule MyAppWeb.SharedView do
  use MyAppWeb, :view
  
  def parse_function(data) do 
    ...
  end

  # return html from view function
  def render("radio_group.html", %{form: f, data: data, field: field) do
    ~E(
         <div class="form-control">
           <%= for l <- parse_function data do %>
           <div class="pretty p-default p-curve">
             <%= radio_button(f, field, elem(l, 1)) %>
              <div class="state">
                <label><%= elem(l, 0)%></label>
             </div>
           </div>
          <% end %>
      </div>
    )
  end

end

If you do not want to return the html in the view function you can create a template for it like any other view template/shared/radio_group.html.eex.

Reference:
sigil_E/2

Phoenix View

The examples shown for rendering custom scripts in the phoenix docs for render_existing/3 really helped me.