At what point can one stand and see the sun rise in the Pacific Ocean and the same sun set in the Atlantic?

Panama, if the Caribbean sea is considered part of the Atlantic Ocean.

To see the sun rise in the Pacific and set in the Atlantic you must go to Panama.
Source: Ripley's Believe It or Not

You'd have to be on the highest point between Pueblo Nuevo Huespital and El Espino - and this is assuming your view wouldn't be blocked by other mountains. And assuming that the Caribbean Sea counts as part of the Atlantic, and the Golfo de Panama counts as part of the Pacific. Sometimes the view from high mountains isn't what people think it's going to be because there are a lot of slightly lower mountains in the way. I would doubt that the sea could be seen from one point on both sides, from the look of the map. The line between the places I named is about the only one where the Pacific lies east of the Atlantic (north of the Equator). The only other possibilty is one of the many little islands at the bottom end of South America. It's not east to find maps of that area, as it is not an area where much happens (news-wise, that is), and defining where the Atlantic and Pacific actually meet is another matter.

According to Wikipedia - From Cerro Jefe, near Panama City, it is possible to see both the Atlantic Ocean and the Pacific Ocean from the same location. This makes Panama the only place in the world where you can see the sun rise in the Pacific and set in the Atlantic.

In the Cerro Azul region and specifically on top of Cerro Jefe at 1,007 meters (Boss Mountain of 3,000 ft) you have a spectacular view of the Panama Canal and with a bit of luck on a clear day you can see both, the Atlantic and the Pacific.

https://es.glosbe.com/es/en/Canal%20de%20Panam%C3%A1

Costa Rica... You can see the sunrise, drive to the other side and watch the sunset.... Carib/Atlantic side for sunrise ...pacific for sunset

This clip demonstrates how the shape of Panama means that there are regions where an arm of the Pacific Ocean is to the east, and a branch of the Atlantic Ocean is to the west. While you may not actually have line-of-sight to sea level, in that region it is true that the sun is rising and setting over the oceans as required. There are several spots where tourists claim they can see the actual water, but it involves some serious climbing to get there.

https://www.youtube.com/watch?v=31Z2LwcypJo