The best picks not in lane to counter Bel'Veth include Kalista, Samira, and Lucian. These are all great at countering Bel'Veth with win rates over 60%. Even if these Bel'Veth counter picks are not taken in the same position as you, it's not a good idea to choose them into these matchups. They will very likely beat Bel'Veth.
Conversely, if the opposite team choses either Rumble or Ziggs, you should seriously think about taking them, as they easily wins against these selections with win rates over 55% against both ofthem.