I'm assuming you're working in ArcMap, If so you can add multiple copies of a single table, shapefile, feature class etc.. Why not import "Friendship" and "Person" twice, assigning your unique relates as desired.
Without more specifics on the relationship classes you want to create, I can't really comment on the data model structure. Your examples, while helpful, don't really demonstrate how you'd like to use the relationship classes.
Los miembros registrados pueden publicar, seguir actualizaciones y más. ¿Nuevo aquí? Regístrate gratis.
Find useful guides, FAQs, and documents to help you navigate and make the most of Esri Community.