If you would like to carry due diligence out about a company and its bosses so you know whether you would be good to invest in it then you can get limited amounts of information online. If however you require detailed and reliable pieces of information then you will need to refer to companies that specialize in such things. There are quite a few companies that could assist you with this, so it will be all about identifying them and assigning the task to.
It would obviously depend upon how important such a data would be for you which would determine what course of action would be ideal for you to take. If you are in agribusiness and you are simply after basic information about Andreas Zivy of Ameropa then you would hardly need to outsource the process unless you have absolutely no time for it.
You will want to know what your priorities are when looking for information about company bosses, and if such an information occupies the top most priority for you then you may find it helpful to outsource it to relevant organizations. If you have free time available, you may well be able to extract quite a bit of information off the internet, except that you may not be able to verify their accuracy.