An expression for you get stuck in small position in big places vs jump to big positions in small cities

Solution 1:

A phrase in this general area is big fish in a small pond.

In my experience people are most likely to use this phrase about themselves to say "I've reached the maximum I can in this small community, I want to show how I can turn that into even more success in a larger community".

However, thefreedictionary.com (citing Farlex Dictionary of Idioms) suggests that it is used exactly as you want: that they wouldn't be as much of a success in the larger community:

A situation in which one person has more power, influence, knowledge, or experience than others within a small group. It often implies that the person may not have as much clout in "a bigger pond," i.e., a larger group or arena of some kind.