Question 2.5 on visa application asks cities and provinces to visit in time sequence

Hi, do you mean you have tickets between US and South Korea, and with transits in Beijing both ways? if yes, you can enjoy the newly released 72 hour free transit in beijing. Please refer to https://www.travelchinaguide.com/embassy/visa/free-72hour/ for details.
Anyway, if you do need a visa, you can just put Beijing to the item 2.5 on the application form.