“выражение параметров” Ответ

Params Expression > [] IncludeProperties

public TEntity GetById(Guid id, params Expression<Func<TEntity, object>>[] includeProperties)
    {
        if (id == Guid.Empty) return null;

        var set = _unitOfWork.CreateSet<TEntity>();
        foreach(var includeProperty in includeProperties)
        {
             set.Include(includeProperty);
        }
        return set.First(i => i.Id == id);
    }