"Joining the panel" means becoming a member or participant in a group of experts or individuals who give their opinions or discuss a particular topic or issue. Full definition
He will join a panel of experts to discuss effective hiring strategies for growing your company. (entrepreneur.com)
Top executives from many of the world's leading real estate firms joined a panel discussion today about the impact of new technology on commercial and residential real estate markets. (nar.realtor)
Both indoor and outdoor dog pens often offer the option of joining panels together for the purpose of creating larger play areas. (puppy-training-solutions.com)