All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
1- If you work for company B outside the working hours as agreed upon with company and if “A” does not prevent you from such working, then there is no blame on you.
2- There is no objection to work for B as a broker and receive 20% for bringing new customers.
3- There is no objection for making business relations between the two companies even though you receive some pay in separate agreement with B, whether this is known to the latter company or not. Then, it is not obligatory to inform A unless there is a condition between you and this company that prevents you from working outside the office hours and this becomes a violation to agreement.
Allah knows best.