Complex sentence: While being geographically located in Chernihiv Raion, (part of Chernihiv Oblast), administratively it belongs to Kiev Oblast, being an administrative exclave, not belonging to any "raion".
Split into simpler sentences: While being geographically located in Chernihiv Raion, (part of Chernihiv Oblast), administratively it belongs to Kiev Oblast. It is an administrative exclave, not belonging to any "raion".