Form.cs

using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace CandyCoded
{

    public class Form : MonoBehaviour
    {

        public Dictionary<string, string> GetFormValues()
        {

            return gameObject.GetComponentsInChildren<FormField>().Where(field => field.name != "")
                .ToDictionary(field => field.name, field => field.value);

        }

        private EventSystem _eventSystem;

        private void Awake()
        {

            _eventSystem = EventSystem.current;

        }

        private void Update()
        {

            if (!Input.GetKeyDown(KeyCode.Tab))
            {
                return;
            }

            var selectable = _eventSystem.currentSelectedGameObject.GetComponent<Selectable>();

            var next = Input.GetKey(KeyCode.LeftShift) || Input.GetKey(KeyCode.RightShift)
                ? selectable.FindSelectableOnUp()
                : selectable.FindSelectableOnDown();

            _eventSystem.SetSelectedGameObject(next.gameObject, null);

        }

    }

}

FormField.cs

using UnityEngine;

namespace CandyCoded
{

    public class FormField : MonoBehaviour
    {

        [SerializeField]
        private string _name;

        public new string name => _name;

        public string value { get; internal set; }

        public void SetValue(string value)
        {

            this.value = value;

        }

        public void SetValue(int value)
        {

            this.value = value.ToString();

        }

    }

}

FormLabel.cs

using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace CandyCoded
{

    public class FormLabel : MonoBehaviour, IPointerClickHandler
    {

        [SerializeField]
        private Selectable _selectable;

        private EventSystem _eventSystem;

        private void Awake()
        {

            _eventSystem = EventSystem.current;

        }

        public void OnPointerClick(PointerEventData eventData)
        {

            _eventSystem.SetSelectedGameObject(_selectable.gameObject, null);

        }

    }

}