You need to fulfill few requirements to do the above mentioned task.
If I understand correctly you need to use your personal computer as a server to host your NodeJS application that running on 8082 port on your local PC.
First of all you need to forward your local computers 8082 port to your public IP address of your home internet connection using your routers configuration. You can ask help for your internet service provider to do this.
Once you do the above task your application will be available to the public using your home internet connections ip address 8082 port. ( You need to allow access to the computers 8082 port in every firewall layer on your network, local computer & maybe in your router too )
then you can add A record in your Google domains portal to point specific sub-domain to your home internet connection's public IP address. This will take some time to propagate.