Make custom user table column filterable

This process is pretty straightforward. Add the following pieces of code to the current ( preferably child ) theme’s functions.php.

Step 1 – add new column to the users table list:

function wpse_add_user_table_list_column($column) {
    $column['call_sign'] = 'Call Sign';
    return $column;
}
add_filter('manage_users_columns', 'wpse_add_user_table_list_column');

Step 2 – make this new column sortable:

function wpse_user_table_list_sortable_columns($columns) {
    $columns['call_sign'] = 'call_sign';
    return $columns;
}
add_filter('manage_users_sortable_columns', 'wpse_user_table_list_sortable_columns');

Step 3 – provide value for this new column:

function wpse_user_table_list_column_value($val, $column_name, $user_id) {
    if('call_sign' === $column_name) {
        // code to set new value ( $new_value )
        return $new_value;
    }
    return $val;
}
add_filter('manage_users_custom_column', 'wpse_user_table_list_column_value', 10, 3);