I have a tricky situation at hand ...
I need to configure my settings on my org. in such a way that :
1. A task related to an account (ACC A) and assigned to a user(say user A) can be edited by anyother user(say user B) who has Read-write access to that account(ACC A). Here users A & B are on the same role(not part of any role hierarchy). Rightnow user B gets an error message 'Insufficient privilege' if he tries to edit the task created using above step.
I am confused as to how we can make this work using sharing rules. My current sharing setting for Activities object is 'Controlled by Parent'. Most importantly I have set off the 'Modify All Data' option on user B's profile as I cannot allow user B to edit data on all objects. And if I set on 'Modify All Data' to true, it works. But my business req. doesn't support that.
Anyone faced with this kind of requirement earlier ? Your advise would be greatly appreciated.