This is the 13169th most frequent Polish word.
ogólnokrajowych
"Ogólnokrajowych" means "nationwide" or "across the entire country."
The word 'ogólnokrajowym' modifies 'poziomie' and means 'at the national level', indicating the scale at which the elections were conducted.
Wybory do sejmu odbyły się na poziomie ogólnokrajowym.
The parliamentary elections were held at the national level.
Using 'ogólnokrajowe' describes the celebrations as encompassing the whole country, emphasizing their wide scope.
Ogólnokrajowe obchody Dnia Niepodległości zgromadziły tysiące ludzi.
The nationwide celebrations of Independence Day gathered thousands of people.
Here, 'ogólnokrajowym' is used to specify that the regulations are applicable across the entire nation.