Here is the solution to List Overlap using functions in Python which is given below:

def listOverlap(num1, num2):

final_list = [ ]

for num in num1:

if num in num2:

final_list.append(num)

return final_list

a = [ ]

b = [ ]

n = int(input("Enter number of elements : "))

for i in range(0, n):

ele = int(input())

a.append(ele)

n1 = int(input("Enter number of elements : "))

for j in range(0, n1):

ele1 = int(input())

b.append(ele1)

print("The common elements in the two lists are: ")

print(listOverlap(a, b))