Get articles based on your county, with county field added to the user column in the database.
Add below in file >> system/library/cart/customer.php

private $county;
private $subcounty;

After Fetch, line 22:

$this->county = $customer_query->row['county'];
$this->subcounty = $customer_query->row['subcounty'];

And in the login function, in the same file.