Can someone explain this part of circuit from BQ500212A?
Those are to provide a delayed start with sleep overriding the snooze.. Snooze and sleep are basically identical but sleep has a longer time constant and overrides sleep. It's all about charging C32 or C22 through different resistors.
D2 is there to let sleep override snooze.
Q8, C34, and R35 bypass sleep and snooze when power is first connected so there is no delay.