What do you do?
Find a translator who knows.
Think of something you know nothing about. Could you write about it? Even in your native language?
Who would you hire to write the material you need translated? An engineer? A chemist? An advertising expert?
Translation is the same. Speaking another language doesn’t give any special insight into specialist subject matter. Translators don’t gain an insight into a specialist subject from a text in a language they understand. Except for the most general of content, the translator needs to be a linguist and a subject matter specialist in one.
Another aspect of specialisation is experience. Would you rather work with someone who has been through the process before and knows the problems and how to avoid and resolve them, or be the blind led by the blind? Train someone in the middle of a project or have someone who can advise you instead?
You can find lists of specialist translators on the sites of professional associations such as the Institute of Translation and Interpreting (ITI) in the UK, the American Translators Association in the USA, the Japan Association of Translators (JAT) in Japan, or through the International Federation of Translators (FIT).