Dear @Engineer_xxx ,
Thank you so much for your interest in our products and for using our community.
Question: select PWM GPIO in PWM1.
Answer: It depends on your needs, PWM outputs that can operate as complementary pairs or independent channels.
If you want PWM outputs operate as an independent channel , you can select one from A0~A3, B0~B3(Total 8 channels).
I suggest you can refer SDK demo "evkbmimxrt1170_pwm_cm7". I think it is very useful for reference.

Question: also if you can explain the picture please will be nice.
Answer: I suggest you can refer chapter 73.4 External signals in MIMXRT1170RM, It describes very detail.
https://www.nxp.com/webapp/Download?colCode=IMXRT1170RM


Wish it helps you.
If you still have question about it, please kindly let me know.
Best Regards
mayliu