Needed this myself and couldn't find an answer. This is working for me.

[POST] https://dev.azure.com/{organisation}/_apis/Contribution/HierarchyQuery?api-version=5.0-preview.1

body: { "contributionIds": ["ms.vss-test-web.testcase-results-data-provider"], "dataProviderContext": { "properties": { "testCaseId":{test_case_id}, "sourcePage": { "routeValues": { "project":"{project_name}" } } } } }