Can you activate Bottomless Trap Hole twice in the same chain?

Answer 1

Once a monster is successfully summoned, the chain afterwards is the summon response chain. Cards like Bottomless Trap Hole are valid at any link in this chain, and multiple response cards can be used against the same summon.

So after a successful summon, Player A passes priority to his opponent, either by activation an Ignition Effect, Trigger, or Spell Speed 2 card, or by passing it manually. Whatever he does, Player B can activate a Bottomless Trap Hole, either adding it as chain link 2 or starting a chain. Player A could activate something like Royal Decree, which will resolve first and negate the Bottomless Trap Hole. So before anything resolves, Player B could add a second BTH to the chain.

This second BTH will resolve first, destroying and removing the monster from play. Royal Decree will resolve and become active next. The first BTH won't do anything now, it will get negated, and even if it didn't, there's nothing for it to affect.

Note though that if Player A had used a Counter Trap against the BTH, then a second cannot be used, as a Spell Speed 2 card can't be chained to Spell Speed 3.