Time tracking reporting

I have a setup where I have a project as Item level and the tasks related to the project are at a sub-item level. The team logs their time at sub-item level and there is no way today to report how much time the team is spending each week / month / quarter. The only time I can report on this is when the sub-item is marked completed.

Is there a way to do this rather than having to extract time log information using API? Very basic reporting that is missing in the tool.