Creating activity summary without revealing details on tasks

Hi J,

Can you post screenshots of the reports that you're using and create a mock-up of what you want the dashboard to look like and post that?

#There are few points that may help you:-

#Several kinds of settings affect your access to events and tasks owned by others in your Salesforce org.

#Role
You have access to view and edit your own activities plus activities assigned to people below you in the role hierarchy of your Salesforce org.
#Permissions
People with the “View All Data” permission can view all activities.
#Sharing Model
When the activity sharing model is “Controlled By Parent,” people with “View All” permission for the type of object on the related record can view the activity.
*Important
Suppose you relate one or more contacts to an activity that other people can view. Those people can view the activity along with the name, account name, and title of each contact you relate to the activity—regardless of whether they can otherwise view that information.
An event with the Private checkbox selected is accessible only by the person assigned to the event.
Example
You can view an activity when one of the following applies:You’re assigned to the activity
You’re above the user assigned to the activity in the role hierarchy
You have at least read access to the record to which the activity is related
You have the “View All Data” permission
You have the “View All” object-level permission for at least one contact and the related opportunity, account or case, and Shared Activities is enabled
You have the “View All” object-level permission for the related opportunity or account, where the sharing model applied to the record is “Controlled By Parent”, and Shared Activities isn’t enabled
You can edit or delete an activity (in Salesforce Classic only) when the following applies:You have the “Edit Tasks” and “Edit Events” permissionsAND
You’re assigned to the activity, or
You’re above the user assigned to the activity in the role hierarchy, or
You have the “Modify All” object-level permission in the related record, where the record’s sharing model is “Controlled By Parent.” (with Shared Activities enabled, you need the “Modify All” object-level permission for at least one contact and the related record), or
You have the “Modify All Data” permission.

Hoping this may help you:

Thanks