I want to create a field where a user can select a nearby mass transit system; so, it must be multiply levels, for example:

- Country #1:

-- City #1:

--- Transit System Name #1
---- Transit Station #1
---- Transit Station #2

--- Transit System Name #2
---- Transit Station #1
---- Transit Station #2

-- City #2:


- Country #2:

-- City #1:

--- Transit System Name #1
---- Transit Station #1
---- Transit Station #2

--- Transit System Name #2
---- Transit Station #1
---- Transit Station #2

I assume I basically follow the same procedures for entering multiple countries.

I would need two fields with the same data entries in case of the rare event that a location is near two mass transit systems.

Any advice you can share would be gratefully appreciated.