Watch the Just A Thought: Overview online guitar lesson by TrueFire from Lead Guitar Greatest Hits Vol. 2
Lesson Source: Jon Finn's Improv Target Practice
Here, the chords, scales and Target Notes are shown, described and demonstrated for "Just a Thought Solo Section". If you're familiar with theory you may realize right away that D aeolian and G Dorian are the same scale, but starting on different degrees. They're essentially the same scale. This also happens between D Ionian and G lydian, as well as Bb Ionian and Eb Lydian. My point: You can change positions for each chord if you want to, but you don't have to.