You may be able to get away with using names in a relationship if your staff is small, but it's almost always better to use an ID number for your staff members instead of their name. Names are not unique, names get changed (even for students) and are also subject to unusual spelling that can make data entry errors easy to commit. Using a serial number from the staffmember table avoids those issues and you still can select by name from a value list if you set up the value list to use both the name and the ID number.
Before we tackle the idea of using a portal to pull up specific records, we need to confirm the basic design of your database system.
I think you set up your relationships initially like this:
Normally, the details for these relationships would look like this:
Staffmembers::__pkStaffID = Tasks::_fkStaffID
Articles::__pkArticleID = Tasks::_fkArticleID
With those relationships, you can place a portal to Tasks on the StaffMembers layout and it will list all tasks assigned to that staff member. Fields from Articles can be included in the portal row to provide a more complete description of each task. In like manner, a tasks portal on the Articles layout would list all tasks associated with that article and fields such as the staffmember's name can be included in the portal to show who was assigned that task.
Please note that this structure assumes that only one person will be assigned to a given task. If multiple staff members can be assigned to the same task, the relationships shown here will need to be modified to support that.