Within the Risk Register Module, there is a Field called Risk Family
Risk Family is a multi-select dropdown used as a grouping mechanism for Risks.
Risk Family has multiple levels and as with all Dropdowns, it is user-defined the levels can be customised and ordered to your requirements.
Risk Family can be used as the primary grouping method (After Register and Division) or as a subsequent grouping method alongside Risk Type, Risk Level, etc
More Information on Dropdowns can be found at the Links Below:
What are the differences between dropdown options? (E.g. Type & Category)