Group By TAGS

Hi
Am trying to create a custom features report where I will like to GROUP BY specific chosen Tags. So fore.g a feature are currently tagged by different geographies, tech, business units. When I group, I will only like for e.g to do so my geographies in my report. How do I do that , I tried exploring formulas (TagObjects.Select(Name)) however struggling to enable it. Will appreciate if you can help me with specific formula or different approach