When Braulio attempts to escape the modified scarf hold as shown in
Part 1 and his opponent switches to the cross side position and blocks his near hip with their arm, he uses his underhook to create space to pummel his shin inside their arm. Once he establishes his shin on their biceps, he replaces it with his foot and extends his leg to give him space to regain an open guard.
Links to other Parts:
Part 1