The short answer is that it cannot.
The slightly more complicated answer is that a company must determine its carbon budget based on a hypothetical global scenario where emissions and the global carbon budget are distributed in a certain way among countries and companies. Then, it needs to establish a very concrete strategy to determine how it's going to spend that carbon budget over the next few years, what it's going to invest in, the activities it's going to undertake and the activities it's going to stop. Then it has to ask itself how it will optimize its processes and what new technologies it will use or stop using, for example.
At that point, we're heading toward something precise, but that implies that we have scaled up a sensible carbon budget. If all the companies in the world do this but don't agree, we can have only carbon-neutral companies, but reach a four-degree Celsius increase, because the carbon budget won't have been used globally.