I can't figure out what goes with what in the top left block, but in the bottom right block take the measurement of the dark green and tan strips after they are sewn together and add 7/8". Cut 2 squares (of dark green (and whatever the other side of that HST is) and cut them that measurement. Sew in the usual HST way and I think you'll have 2 squares that fit those corners. Try in on trash fabric and see if it works.