Watch the Option E online guitar lesson by Brad Carlton from Chord Studies: Rock and Pop Progressions Vol. 2

In example one you are playing over a triplet feel which could also be labeled a 12/8 feel. When moving from the Gm to E♭, you have some options. You could barre three strings for a half barre, or you could do a 2/3 barre which will you help you get in place for your B♭chord. As you repeat the progression and return to Gm your third finger will be a pivot finger.