Laravel Eloquent With() With()

nested relations

 with('relation1.relation2.relation3')->get(); // relation1 has relation2 relation2 has relation 3

not nested relations

 with('relation1','relation2','relation3')->get(); // you model has all relations

You need Nested Eager Looading

PortalPlaylistElement::with('AirtimePlaylists.AirtimePlaylistContents')->get();