Create 2 bools to store the state of the triggers (bLeftTriggerPressed and bRightTriggerPressed or something more generic unrelated to the button name, like bFirstModifierKeyPressed and bSecondModifierKeyPressed) and set them to true on pressed, and false on released.
When you press the B button you can check if these two values are true and perform a soecific action instead of (or in addition to) the regular one.
You could also check if these keys are pressed without the bools at runtime, but I wouldn’t recommend this because if you change the input mapping (for example from LT and RT to LB and RB) you will have to edit these checks