This video shows a two-person bunkai flow-drill for Pinan / Heian Sandan. The video is a short summary of several hours of practise and therefore it should not be viewed as an “instructional clip”.
The flow-drill shown puts several piece of bunkai from Pinan / Heian Sandan end to end in the same order they appear in the kata. It is but one form of practise and the bunkai also needs to be drilled live (Kata-Based-Sparring), individually, and in alternate sequences. A four minute video can obviously not convey the entirety of a training regimen.