.NET Core: How to merge nested one-to-many relations in dto

Question

How could merge nested child entity in parent?

I have these three entities:

public class Faculty
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public ICollection<Group> Groups { get; set; }
}

public class Group
{
    public Guid Id { get; set; }
    public string Name { get; set; }
    public ICollection<User> Users { get; set; }
}

public class User
{
    public Guid Id { get; set; }
    public string Name { get; set; }
}

Expected results in ResultDto is:

public class ResultDto
{
    public Guid FacultyId { get; set; }
    public string FacultyName { get; set; }
    public ICollection<User> Users { get; set; }
}