Read a field from another dissector in C

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I have a post dissector written in LUA which access a field from another dissector using

other_dissector_field = Field.new("otherdissector.flag.success")

The field otherdissector.flag.success is defined in another dissector and can now be used in my post dissector, can this be implemented in a C post dissector and could you show me the code to do this ?