Prevent a GameObject from leaving a particular region

Unity Engine
1

I’m trying to prevent a GameObject from leaving a particular region. Now the hard part is that the region doesn’t have to be rectangular shaped so what I’ve been doing so far–clamping the x & y values of the GameObject’s destination to the min/max bounds of the shape–will not work. I need a to find a way to constrain the GameObject to the shape defined in the class. The GameObject is also a kinematic rigidbody so that make things a bit more difficult.

This is some of the code I have so far (WIP):

public class Prisoner2D : Component
    {
        [SerializeField] private Movement _movement;
        [SerializeField] private Collider2D _prison;

        private Bounds _bounds;

        private void Start()
        {
            _movement.OnStarted.AddListener(MoveTo);
            if (_prison != null)
            {
                _bounds = _prison.bounds;
            }
        }

        public void SetPrison(Collider2D prison)
        {
            _prison = prison;
            _bounds = prison.bounds;
        }

        public void MoveTo(Vector2 position)
        {
            Vector2 min;
            Vector2 max;

            if (!_prison.gameObject.isStatic)
            {
                var bounds = _prison.bounds;
                min = bounds.min;
                max = bounds.max;
            }
            else
            {
                min = _bounds.min;
                max = _bounds.max;
            }

            float x = Mathf.Clamp(position.x, min.x, max.x);
            float y = Mathf.Clamp(position.y, min.y, max.y);
            var destination = new Vector2(x, y);
            _movement.MoveTo(destination);
        }

        public void MoveTo(Vector3 position)
        {
            Vector2 position2D = position;
            MoveTo(position2D);
        }
    }
2

Simple approach is to use a different collision layer - Unity - Manual: Layer-based collision detection