ios - Headers not finding files inside folders -

i'm working nested project have bunch of files inside folders; problem comes when import them. error saying file not found. if type name of parent folder, slash , file name seems work ok. so, have type #import "folder/file.h" instead of #import "file.h". i'm aware there's automatic way this.

i assume issue can solved modifying of parameters on build phases. i'm not sure do. give me advice? thanks

edit: error occurs when archive. when build & run don't error.

there more elegant way of doing that. however, typically solve adding files xcode project.