Django, keep initial url path unchanged

I have a Django project with 5 apps. Basically, in the homepage there are 3 links. I’m still not in deployment so the base url is localhost:8000 (the homepage app is called homepage). After the user clicks in one of the 3 links I want the url to stay with that number, even after using different apps.

Example of what I’m looking for: User clicks on link 1 and then → localhost:8000/1. User clicks on link that directs to another app (called ros) → localhost:8000/1/ros. And keep that one at the start of the url and only change if another of the 3 links in homepage is selected.

Example of what I’m getting so far: User clicks on link 1 and then → localhost:8000/ros/1 or localhost:8000/ros/2 or localhost:8000/ros/3 depending on the link clicked.

The question is, how can I modify the homepage URL’s and the app ROS url’s so that the ROS url receive the link parameter (either a 1,2 or 3) + ROS.urls.

HTML homepage code

<li><a href="/" class="nav-link scrollto"><i class="bx bx-home"></i> <span>Inicio</span></a></li>
        <li><a href="1/ros/1" class="nav-link scrollto"><i class="bx bx-file-blank"></i> <span>ROS 1</span></a></li>
        <li><a href="2/ros/2" class="nav-link scrollto"><i class="bx bx-file-blank"></i> <span>ROS 2</span></a></li>
        <li><a href="3/ros/3" class="nav-link scrollto"><i class="bx bx-file-blank"></i> <span>ROS 3</span></a></li>

Homepage URL patterns

urlpatterns = [

ROS URL patterns

urlpatterns = [

Thanks, any guidance would be helpful.

I am probably missing some important point, but putting links in the home page template like:

<a href="1/{% url 'index_ros' ros_id=<!--some value--> %"}>some text</a>
<a href="2/{% url 'index_ros' ros_id=<!--some value--> %}">some text</a>
<a href="3/{% url 'index_ros' ros_id=<!--some value--> %}">some text</a>

Then, if you want to carry that over on to other pages you need another URL pattern:

path('<int:ref>/ros/<int:ros_id>/', views.index_ros, name='index_ros_referrer')

Then on the template:

<a href="{% url 'index_ros_referrer' ref=<!--some other value--> ros_id=<!--some value--> %}">some text</a>