The easiest way is set Settings -> Network -> Adapter 1 -> Bridged Adapter (Default should be NAT). It shall make the VM part of your local network, getting ip from DHCP.
Check your IP address of your VM client (Ubuntu).
ifconfig -aeth3 Link encap:Ethernet HWaddr 08:00:27:2b:31:6c
inet addr:192.168.0.176 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::fac6:2bd6:2e9:5f3c/64 Scope:Link
inet6 addr: 2001:e68:542c:1838:e3fb:a14a:283c:bc4d/64 Scope:Global
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:9662 errors:0 dropped:0 overruns:0 frame:0
TX packets:7491 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5760005 (5.7 MB) TX bytes:1119239 (1.1 MB)
Interrupt:19 Base address:0xd020 My VM's ip is 192.168.0.176. I have a nginx server running, so I can use the host browser to access http://192.168.0.176.