Roadmap group by objectives does not work for themes

Issue Summary

In Live Roadmap, themes are not displayed while trying to group by objectives.

Steps to Reproduce

1. Associated some objectives to themes in the objective slide-out panel.
2. Navigate to the roadmap and select Work from the first dropdown and Themes from the second dropdown.
3. In Configurations > Other Options > Select Group By > Objectives. 

Expected Results

Themes are grouped by objectives.

Actual Results

No objectives are displayed.
 

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available