I am a Premier Platinum member. So my companions with non basic economy tickets can get an Economy Plus seat on the same flight.
I have done this multiple time when I travel on regular economy class tickets and I enjoyed seating together with my companions.

This time I booked a Business class ticket for myself and my family member booked a non basic economy ticket on the same flight.
So we will not be seating together. I am wondering if my family member can get an Economy Plus seat in this case.

Thank you.