splitting dirs into variables?

[DeaD_EyE]

If you collect first all files in a list, then you have to classify them all afterwards by country and year.
A different approach is to scan the directories, to acquire the information and then return pairwise the files.

from pathlib import Path
from pprint import pprint


def easier_grouping(root):
    root = Path(root)
    for year in root.iterdir():
        if year.is_dir() and year.name.isdecimal():
            for country in year.iterdir():
                ics_root = country / "ICS"
                xls_file = ics_root / "Work" / f"{country.name} profile inflation {year.name}.xls"
                xlsm_file = ics_root / f"{country.name}_taxcheck_{year.name[-2:]}.xlsm"
                if xls_file.exists() and xlsm_file.exists():
                    yield xls_file, xlsm_file


pprint(dict(easier_grouping("Tax scripts")), indent=4)

Output:
{   WindowsPath('Tax scripts/2020/Germany/ICS/Work/Germany profile inflation 2020.xls'): WindowsPath('Tax scripts/2020/Germany/ICS/Germany_taxcheck_20.xlsm'),
    WindowsPath('Tax scripts/2020/Hungary/ICS/Work/Hungary profile inflation 2020.xls'): WindowsPath('Tax scripts/2020/Hungary/ICS/Hungary_taxcheck_20.xlsm')}