SilverStripe unable to populate multiple member Childs

Question

I have 3 type of users salesman => has many buyers buyer => has many agents agent has none child

so I want to list all the buyers associate with that salesman when viewing salesman and all the agents when viewing buyer in admin

class MemberExtension extends DataExtension
{
    private static $has_one = [
      'RefSalesman'    => Member::class,
      'AgentOwner'     => Member::class,
    ];

    private static $has_many = [
        'Buyers'                 => Member::class,
        'Agents'                 => Member::class,
    ];

    private static $summary_fields = [
      'RefSalesman.Name'    => 'Ref Salesman',
      'AgentOwner.Name'    => 'Agent Owner',
    ];

This way I am only able to see agents listing under buyers but no buyers when viewing salesman.

Answer 1

These has-many relations do not know to which has-one they are referring to. Being both the same class, you must explicitely specify the destination relation in dot notation: see the has-many documentation for details.

private static $has_many = [
    'Buyers'                 => Member::class.'.RefSalesman',
    'Agents'                 => Member::class.'.AgentOwner',
];