Is it possible to get a tree of work items in a test plan without parent/child links?

Im working with a project in TFS (2017) where a test plan has been made along with suites and cases that have no relationship between them (that is, no links or parent/child relationship). In other words, they are all top level according to any queries I run. I was wondering if there was any other relationship without having to link all of these work items that could be used to query the test plan and return a tree of work items?