Help understanding when a boolean is set to true

private void Patroling()
{
if (m_PlayerNear)
{
// Check if the enemy detect near the player, so the enemy will move to that position
if (m_TimeToRotate <= 0)
{
Move(speedWalk);
LookingPlayer(playerLastPosition);
}
else
{
// The enemy wait for a moment and then go to the last player position
Stop();
m_TimeToRotate -= Time.deltaTime;
}
}

can anyone tell me where the bool m_PlayerNear is actually set to true.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
public class AIController : MonoBehaviour
{
    public NavMeshAgent navMeshAgent;               //  Nav mesh agent component
    public float startWaitTime = 4;                 //  Wait time of every action
    public float timeToRotate = 2;                  //  Wait time when the enemy detect near the player without seeing
    public float speedWalk = 6;                     //  Walking speed, speed in the nav mesh agent
    public float speedRun = 9;                      //  Running speed

    public float viewRadius = 15;                   //  Radius of the enemy view
    public float viewAngle = 90;                    //  Angle of the enemy view
    public LayerMask playerMask;                    //  To detect the player with the raycast
    public LayerMask obstacleMask;                  //  To detect the obstacules with the raycast
    public float meshResolution = 1.0f;             //  How many rays will cast per degree
    public int edgeIterations = 4;                  //  Number of iterations to get a better performance of the mesh filter when the raycast hit an obstacule
    public float edgeDistance = 0.5f;               //  Max distance to calcule the a minumun and a maximum raycast when hits something


    public Transform[] waypoints;                   //  All the waypoints where the enemy patrols
    int m_CurrentWaypointIndex;                     //  Current waypoint where the enemy is going to

    Vector3 playerLastPosition = Vector3.zero;      //  Last position of the player when was near the enemy
    Vector3 m_PlayerPosition;                       //  Last position of the player when the player is seen by the enemy

    float m_WaitTime;                               //  Variable of the wait time that makes the delay
    float m_TimeToRotate;                           //  Variable of the wait time to rotate when the player is near that makes the delay
    bool m_playerInRange;                           //  If the player is in range of vision, state of chasing
    bool m_PlayerNear;                              //  If the player is near, state of hearing
    bool m_IsPatrol;                                //  If the enemy is patrol, state of patroling
    bool m_CaughtPlayer;                            //  if the enemy has caught the player

    void Start()
    {
        m_PlayerPosition = Vector3.zero;
        m_IsPatrol = true;
        m_CaughtPlayer = false;
        m_playerInRange = false;
        m_PlayerNear = false;
        m_WaitTime = startWaitTime;                 //  Set the wait time variable that will change
        m_TimeToRotate = timeToRotate;

        m_CurrentWaypointIndex = 0;                 //  Set the initial waypoint
        navMeshAgent = GetComponent<NavMeshAgent>();

        navMeshAgent.isStopped = false;
        navMeshAgent.speed = speedWalk;             //  Set the navemesh speed with the normal speed of the enemy
        navMeshAgent.SetDestination(waypoints[m_CurrentWaypointIndex].position);    //  Set the destination to the first waypoint
    }

    private void Update()
    {
        EnviromentView();                       //  Check whether or not the player is in the enemy's field of vision

        if (!m_IsPatrol)
        {
            Chasing();
        }
        else
        {
            Patroling();
        }
    }

    private void Chasing()
    {
        //  The enemy is chasing the player
        m_PlayerNear = false;                       //  Set false that hte player is near beacause the enemy already sees the player
        playerLastPosition = Vector3.zero;          //  Reset the player near position

        if (!m_CaughtPlayer)
        {
            Move(speedRun);
            navMeshAgent.SetDestination(m_PlayerPosition);          //  set the destination of the enemy to the player location
        }
        if (navMeshAgent.remainingDistance <= navMeshAgent.stoppingDistance)    //  Control if the enemy arrive to the player location
        {
            if (m_WaitTime <= 0 && !m_CaughtPlayer && Vector3.Distance(transform.position, GameObject.FindGameObjectWithTag("Player").transform.position) >= 6f)
            {
                //  Check if the enemy is not near to the player, returns to patrol after the wait time delay
                m_IsPatrol = true;
                m_PlayerNear = false;
                Move(speedWalk);
                m_TimeToRotate = timeToRotate;
                m_WaitTime = startWaitTime;
                navMeshAgent.SetDestination(waypoints[m_CurrentWaypointIndex].position);
            }
            else
            {
                if (Vector3.Distance(transform.position, GameObject.FindGameObjectWithTag("Player").transform.position) >= 2.5f)
                    //  Wait if the current position is not the player position
                    Stop();
                m_WaitTime -= Time.deltaTime;
            }
        }
    }

    private void Patroling()
    {
        if (m_PlayerNear)
        {
            //  Check if the enemy detect near the player, so the enemy will move to that position
            if (m_TimeToRotate <= 0)
            {
                Move(speedWalk);
                LookingPlayer(playerLastPosition);
            }
            else
            {
                //  The enemy wait for a moment and then go to the last player position
                Stop();
                m_TimeToRotate -= Time.deltaTime;
            }
        }
        else
        {
            m_PlayerNear = false;           //  The player is no near when the enemy is platroling
            playerLastPosition = Vector3.zero;
            navMeshAgent.SetDestination(waypoints[m_CurrentWaypointIndex].position);    //  Set the enemy destination to the next waypoint
            if (navMeshAgent.remainingDistance <= navMeshAgent.stoppingDistance)
            {
                //  If the enemy arrives to the waypoint position then wait for a moment and go to the next
                if (m_WaitTime <= 0)
                {
                    NextPoint();
                    Move(speedWalk);
                    m_WaitTime = startWaitTime;
                }
                else
                {
                    Stop();
                    m_WaitTime -= Time.deltaTime;
                }
            }
        }
    }

    private void OnAnimatorMove()
    {

    }

    public void NextPoint()
    {
        m_CurrentWaypointIndex = (m_CurrentWaypointIndex + 1) % waypoints.Length;
        navMeshAgent.SetDestination(waypoints[m_CurrentWaypointIndex].position);
    }

    void Stop()
    {
        navMeshAgent.isStopped = true;
        navMeshAgent.speed = 0;
    }

    void Move(float speed)
    {
        navMeshAgent.isStopped = false;
        navMeshAgent.speed = speed;
    }

    void CaughtPlayer()
    {
        m_CaughtPlayer = true;
    }

    void LookingPlayer(Vector3 player)
    {
        navMeshAgent.SetDestination(player);
        if (Vector3.Distance(transform.position, player) <= 0.3)
        {
            if (m_WaitTime <= 0)
            {
                m_PlayerNear = false;
                Move(speedWalk);
                navMeshAgent.SetDestination(waypoints[m_CurrentWaypointIndex].position);
                m_WaitTime = startWaitTime;
                m_TimeToRotate = timeToRotate;
            }
            else
            {
                Stop();
                m_WaitTime -= Time.deltaTime;
            }
        }
    }

    void EnviromentView()
    {
        Collider[] playerInRange = Physics.OverlapSphere(transform.position, viewRadius, playerMask);   //  Make an overlap sphere around the enemy to detect the playermask in the view radius

        for (int i = 0; i < playerInRange.Length; i++)
        {
            Transform player = playerInRange*.transform;*

Vector3 dirToPlayer = (player.position - transform.position).normalized;
if (Vector3.Angle(transform.forward, dirToPlayer) < viewAngle / 2)
{
float dstToPlayer = Vector3.Distance(transform.position, player.position); // Distance of the enmy and the player
if (!Physics.Raycast(transform.position, dirToPlayer, dstToPlayer, obstacleMask))
{
m_playerInRange = true; // The player has been seeing by the enemy and then the nemy starts to chasing the player
m_IsPatrol = false; // Change the state to chasing the player
}
else
{
/*
* If the player is behind a obstacle the player position will not be registered
* */
m_playerInRange = false;
}
}
if (Vector3.Distance(transform.position, player.position) > viewRadius)
{
/*
* If the player is further than the view radius, then the enemy will no longer keep the player’s current position.
* Or the enemy is a safe zone, the enemy will no chase
* */
m_playerInRange = false; // Change the sate of chasing
}
if (m_playerInRange)
{
/*
* If the enemy no longer sees the player, then the enemy will go to the last position that has been registered
* */
m_PlayerPosition = player.transform.position; // Save the player’s current position if the player is in range of vision
}
}
}
}

Well, it’s never set to true, at least nowhere in the code you provided. We can’t really say anything more than that. If this is from some kind of tutorial, you may have not completed it or you missed that part, somehow.