Never flown the 777, but I suspect it's the same as the 737.
The V/B and V/S are giving information on the vertical bearing and the V/S required to reach the WPT/ALT entered on line 3R - that is, to reach the waypoint AT the altitude entered.
It doesn't take into account any level/speed restrictions entered in the legs page or the descent page.
You can change the WPT/ALT on 3R to whatever you want - it won't change the calculated VNAV profile. The WPT can be any waypoint that is stored in the FMC. It doesn't have to be on your route.
Keep in mind that the V/S information assumes your current groundspeed all the way to the waypoint.
Last edited by shaftsburn; 27th May 2016 at 18:25.