It doesn't matter which nodes are at the ends, but it does matter that the terminators are at each end.
The bus is a transmission line. To edges from reflecting at the ends of the cable, the cable has to be terminated with its characteristic impedance. The common standard for CAN is twisted pair with 120 Ω impedance. You therefore need 120 Ω at each end of the cable. This 60 Ω load is considered in the drive levels and signaling levels.
In CAN, termination of the bus serves a second purpose, which is to passively hold the two lines together when nothing is driving the bus. This is like a pullup resistor on a open collector bus. The terminators work like a pull-together resistance.
You have another confusion. You terminate the bus, not nodes. Therefore your question of which to nodes to terminate makes no sense. The bus is terminated at its ends, and the nodes can go anywhere along that bus. The bus can extend past the last node at each end, for example.