usually, the camera tends to open up the lens aperture as much as it can to maximize the light capture at night, this will make the depth of field smaller, hence you cannot focus BOTH the front and the background in sharp focus

you can try set the appropriate aperture value to be able to capture both but the ISO will increase and the shutter speed will decrease
ISO raised means poorer picture quality, lower shutter speed means easily blurred pictures

if your camera cannot get you a satisfactory picture, try shooting the scene using black and white while bump up the ISO to very high, this way, you may get sharp pictures and can focus both front and background, happy testing

What about using manually flash for the front object then focus on the far object at night?

if the background objects are well lit, you might be able to get them both in focus if you use smaller aperture
the flash will hit the front objects and bounces back but not much light bounces back from the background
use manual setting, make sure both front and back in focus, and fire up the flash, you might get lucky if the background image comes back well lit

any sample photo u take of this?

the result really depends on the quality and size of the lens and sensor
not all camera created equal
keep shooting and experiment with different settings
cheerz

Has anyone already mentioned something about photo editing? I've found a nice article about diverse tutorials on Youtube - http://fixthephoto.com/blog/retouch-tips/b...on-youtube.html. It has a lot of useful tips about portrait retouching, color adjusting, wedding photo post processing, etc.