Watch the Stay On Four online guitar lesson by Brad Carlton from Chord Studies: Open String Chords Vol. 2
This progression is a iii-IV-V in the key of G. Your first chord is a Bm7/11 - be sure to keep those fingers upright. We've got an easy change to the Cadd9 with your fourth finger acting as a pivot. Pick up your third finger and bring the second finger over and you've got the Dsus2. You're going to keep finger four right where it is for the D, which may be different than your usual way of fingering it but it allows us to keep finger four as a pivot throughout.