Place the first component in the line.
Place the second component into the line and connected to the connect point of the first component. You can see that the connect points are actually joined by the black rectangle in the Drawing view:
While holding down the ALT key, drag one component along the line away from the other leaving the desired distance between the two.
If the components are already close to each other but not connected at coincident connect points, you must drag one component off of the segment to disconnect it and then move it back to get the connect points attached.