Conversation so far:
What committee assignments did Tim Kaine take part in?
Kaine was on the Committee on Armed Services, the Committee on the Budget, and the Committee on Foreign Relations
What did Tim Kaine do on the committee of Armed Services?
Kaine is a member of the Subcommittee on Emerging Threats and Capabilities, the Subcommittee on Readiness and Management Support (for which he is the ranking member), and the Subcommittee on Seapower.

Question: What title did he hold?
Self-contained rewrite: What title did Tim Kaine hold?