ReportNet - Multi level reporting & use of Tabular Set & Reference

[HRAnalytics]

Hi all, relatively new to CRN, I need to display within a series of reports at Department level, totals at differing levels of organisation hierarchy eg.

Avg.Headcount Nos.of.Leavers Turnover
Company xxx xxx xxx
Division xxx xxx xxx
Dept xxx xxx xxx

These need to be done at the lowest level of grain, ie, Department, because they are then distributed to every dept.mgr. Each sub-report needs to show metric values such as turnover or absence rates at dept,div, & company levels. What is the best approach? Can I make use of tabular SQL or Reference, and if so, how?
Thanks
Graham