From a Host Page, e.g. https://foreman/hosts/foo.example.com, when the user clicks on the hostgroup and the host group is nested, the linked URL follows this pattern:

https://foreman/hosts?search=hostgroup+%3D+<level1Group>%2F<level2Group>
https://foreman/hosts?search=hostgroup+%3D+<level1Group>%2F<level2Group>%2F<level3Group>

These searches always produce zero results, since the proper URL would be (respectively):

https://foreman/hosts?search=hostgroup+%3D+<level2Group>
https://foreman/hosts?search=hostgroup+%3D+<level3Group>

I'm not sure whether the proper solution is to fix the html rendered to the browser or change how the host group membership data is stored such that the existing search lingo would function as expected.