Entity Framework query using navigation properties -

users have many roles. roles have many privileges. need list of privileges assigned user based on roles user may have. have in mind gives me ienumerable of ienumerable of privilege:

list<privilege> privileges = user.roles.select(r=>r.privileges.where(p=>p.isactive)); 

how can using navigation properties?

selectmany 

it flattens ienumerables go