Hi Dan,

Thank you for your feedback.

Gantter does not currently have a feature that is exactly the same as subprojects in MS Project. However, you are able to see reports based on multiple projects at a time using the "Visualization" feature. Please use the following steps:
1. Go to the Gantter home page. 

2. Select more than one project on the home page, the button at the bottom-right of the screen will change to show the visualization option.

3. Click on the button at the bottom-right of the screen

4. Once the visualization have loaded, you will be able to use the tabs to see different reports based on the projects you had selected.