Display Downstream (child) Pipelines in Sidebar

Problem to solve

The sidebar view showing the "Latest Pipeline for this branch" is very useful, but it doesn't show any jobs that trigger child pipelines, or the child pipelines themselves.

The CI setup for my workplace's monorepo starts with a "change detection" job that figures out which sub-apps to run CI pipelines for (and those can create one more layer of child pipelines), and I'd like to be able to see these in the sidebar.

Proposal

Add extra nodes in the sidebar for downstream pipelines, nesting them in the tree. A maximum depth of 2-3 levels would be fine.

Further details

Here is a "pipeline view" not showing the lang-js child pipeline:

Whereas the Gitlab.com UI displays it under "Downstream":

Links / references