There is no direct way for Area Wise/Route Wise or Account Group Subgroup in Book Keeper.
Make sure you are creating account group subgroup as per below notation:
Customer E-Marine Drive-Mumbai
Customer F-Vijaya Nagar-Banglore
Customer G-Vijaya Nagar-Banglore
It will create group/subgroup like this:
Video: How to create group/subgroup: https://www.youtube.com/watch?v=B4RVMhAbifQ
To view route wise/area wise sales:
1. Go to Report > Sales Register report and click Open In Excel button:
2. Select row 4 and then on top, click Data > Filter
3. Click on Particulars > Text Filters > Contains:
4. Type the route name you want to track and click OK. It will show you details only for that particular area/route. Same way you can check for other routes as well.