This very short clip looks at bunkai for the “elbow” followed by the three “reinforced lower blocks” found toward the end of Passai / Bassai-Dai. Commonly explained as a series of rapid “reinforced” kick blocks (such as one may need if attacked by an angry can-can dancer!), I would suggest that a more pragmatic way of viewing the move is simply striking the enemy, and then pulling them on for a second strike.
The footage was filmed after training in response to a request. It was a warm day and it was filmed by my daughter (hence the lens steaming up and the very slight camera wobbles ;-).
I hope you find it of interest!
All the best,
PS The YouTube link can be found HERE