tests_dict = {'test 1': ['Manuel', 'Mariana', 'Filipa'], 'test 2': ['Manuel', 'Filipa', 'Mariana'], 'test 3': ['Mariana', 'Manuel', 'Filipa']}
peps_dict = {n: {test: tests_dict[test].index(n) + 1 for test in tests_dict if n in tests_dict[test]} for n in (name for listN in tests_dict.values() for name in listN)}
print(peps_dict)