Hi,
I’m currently actively studying the Wireguard documentation, but I can’t say that I’m good at it 
But, if you use a mobile device as a WG client, in my case it is an iPhone, in the WG APP client settings when editing allowed IPs, it is possible to activate the button “exclude private IPs”.
Then you can simply add to the list of allowed ip wich you need to access your local network. For example, your Brume2, as address 192.168.1.1/32 and you will have an access to your Brume from your mobile phone, while other IP addresses on the same subnet will not be available. For me it works. But I find it useless as an elevated user can always edit the profile and override excluded private addresses and access them.