【Unity】対象の Transform を親に持つかどうかを調べる拡張メソッド

public static class TransformExtension
{
    public static bool HasInParent(this Transform self, Transform target)
    {
        var current = self;
        while (current.parent != null)
        {
            if (current == target)
                return true;
            current = current.parent;
        }
        return false;
    }
}

transform.HasInParent(target); // target を親にもつかどうか