如何从laravel中的数据透视表中获取更多行

Question

Hi I am trying to build an app where there are parent elements which have children and each child has its own sub child. I am having a pivot table which consists of user_id, plan_id and child_id, Now I am trying to fetch the child. How can I fetch all the children in an array.:

I am trying following code:

$user = Auth::user();
$selectplan = 1;
$children = $user->relations()->wherePlanId($selectplan)->first()->pivot->child;

I am able to get only first child, but I have more rows to be fetched:

/**** Table Column ****
*
*
/--id----user_id----plan_id----child----created_at----updated_at
    1        1         1         2        NULL          NULL
    1        1         2         3        NULL          NULL
    1        1         1         4        NULL          NULL
    1        2         1         7        NULL          NULL
    1        2         1         8        NULL          NULL
    1        2         3         10       NULL          NULL

Please help me out. Thanks!