Confidential tasks
By default, a task is visible to all project members. However, you have the option of marking a task as confidential.
The task will then only be visible to the members assigned to the task and the members participating in the project with administrator rights.
In the What tab of the task: click on the padlock icon to the right of “Confidential task”: 
When confidentiality is active, the icon turns blue: 
In the What view, a small padlock icon appears on the task: 
To turn confidentiality off, click the “Confidential task” toggle button again in the What tab of the task details panel.
To know more about:
- How to assign members to the tasks: https://www.beesbusy.com/resources/features/tasks/assign-members-task/
- How to manage the members rights on the project: https://www.beesbusy.com/resources/features/project/share-project-with-members-manage-access-rights/