You add additional queues at the exit of the conveyors. You close the input of the queues. You create a tasksequence to transport an item by the elevator.
The OnLoad Trigger of the elevator moves items to a queue (green), that is connected to the conveyor on the elevator. The exit of the elevator is connected to annother queue (red). The input of this queue is generally closed. By this the item is going to stay at the end of the elevator. The tasksequence will transfer from the item any object to the destination.

Conveyor, both queues (green, red) are moved into the elevator. The animated gif shows you the queues are moving up and down with the elevator. You can set the queue and their contents invisible later. Then you won't see them anymore.
conveyor-on-elevator.fsm