Redmine

When clicking on Administration -> Trackers -> <click on tracker name> you get to the "Tracker Edit" View. On the right-hand side of the page, you see the list of all projects with this tracker in the "Projects" fieldset/group box (see attachment).

Unfortunately, if there are many nested projects in this list, there is a vertical scrollbar for each level (in your case 4!).

To improve this, you could simply make the fieldset bigger (= higher) as there is enough space left below it.