That 192.168.99.101 is Docker host’s IP address internal to Computer A. You only need to config port forwarding from defaut
's port 8069 to host machine' port 8069. Then odoo
will be accessible by computer B with computer A's ip address(ex: 10.0.1.22) plus port 8069. Since both computers are within the same network, you shouldn't need to change settings of your router(except firewall settings, if there is any)
10.0.1.22:8069
Port forwarding need to be set in virtulbox settings