import re
nextline = (
    """DD:MM:YYYY INFO - 'WeeklyMedal: Hole = 1; Par = 4; Index = 2; Distance = 459; Score = { Player1 = 4; Player2 = 6; Player3 = 4 };"""
    )
my_regex = re.compile('\\w+ \\= \\w+')
final_dict = {'Hole': 0, 'Par': 0, 'Index': 0, 'Distance': 0, 'Score': {}}
filtered_items = my_regex.findall(nextline)
for item in filtered_items:
    key = item.split(' = ')[0]
if key.startswith('Player'):
    final_dict['Score'][key] = int(item.split(' = ')[1])
else:
    final_dict[key] = int(item.split(' = ')[1])
разделить строку на словарь с несколькими слоями пар ключ-значение