Playing the Key of G in 3rds on the Mandolin

"And finally this is an exercise to kind of test the brain and the hand functions once you get used to all this stuff. We're going to play in the key of G. And I'm going to use the same shape, we use the root position, but then you can translate that to the other inversions. And I'm going to move through the key of G in thirds. Playing the right thirds so in the key of G the G chord is the one o.k? And then I'm going to play a B minor o.k? After that I'm going to play a D major chord o.k? After that I'm going to play an F sharp diminished. A minor, C, E minor and then back to G."