Put a code into a another, python totally new, im learning in the process, Raspberry

Question

So im trying to put this:

import time
import RPi.GPIO as GPIO

def lrelay():
    
    GPIO.setmode(GPIO.BCM)

    GPIO.setwarnings(False)
    GPIO.setup(27, GPIO.IN)
    GPIO.setup(5, GPIO.OUT)
    GPIO.output(5, True)
    
    BS1=False
    
    try:
        def switch(ev=None):
            global BS1
            BS1 = not BS1
            
            if BS1 == True:
                GPIO.output(5, GPIO.HIGH)
            else:
                GPIO.output(5, GPIO.LOW)
        def button():
            GPIO.add_event_detect(27, GPIO.FALLING, callback = switch, bouncetime=300)
            
        def wait():
            while True:
                time.sleep(1)
        
        button()
        wait()

    finally:
        GPIO.cleanup()
        

into this one:

from feed import feeding
from water import pumpwater
from lightsonoff import lrelay
from multiprocessing import Process

if __name__ = "__main__":

    w = Process(target=pumpwater)
    f = Process(target=feeding)
    l = Process(target=lrelay)

    w.start()
    f.start()
    l.start()

    w.join()
    f.join()
    l.join()

but, every time I push the button it tells me that BS1 is not define, when I run lightsonoff alone, works, but when I put it in the main program it do not work, please help, I do not know what to do T_T