Understanding Bi-Wheel Aspect Chart Lines
By reviewing the following screenshots it should become clear how the aspect chart lines are displayed for bi-wheel charts.
In the first screenshot, all progressed to natal aspects lines are shown. Aspect lines should be viewed from the progressed (outer points/planets) to inner wheel points/planets. The large blue line shows the aspect clearly – Moon progressed in Gemini is square the natal Sun. The two smaller blue lines point to the actual corresponding aspect line.
This screenshot should make the above apparent:
Selecting an aspect in the Moon aspect table results in the chart showing only that particular aspect. See also the post Isolating Bi-Wheel aspects.