Notification at sub-group level

[#1]

Why is this feature important to you:
This feature is important because we are unable to customize or control notifications at the group or subgroup level. As a result, stakeholders (such as my VP) are receiving irrelevant messages that do not pertain to our specific project, which causes confusion and impacts communication effectiveness.
How would you like the feature to work:
Ideally, we would like the ability to configure notifications at the subgroup level independently of the parent group. While the system currently allows notification settings at the parent group level, it does not support differentiated configurations for subgroups or nested groups. The feature should allow for subgroup-specific notification settings to meet the needs of different project teams using the same structure.
Current Behaviour:
Currently, the system only allows notification configuration at the parent group level. It is not possible to set different notification rules for individual subgroups, which limits flexibility across multiple projects sharing the same group structure.