Are you familiar with input/outputs?
Should the other be pressed before the other or at the same time?
If the other must be pressed before the other:
Go to the secondary buttons properties and make it start locked and then to the first buttons properties where you make it send an unlock output to the second button. (or just use filters) Got it?
Same time:
I dont know how to do this sorry... maybe a logic_counter with inputs that reset it after a time and the counter has to reach 2 for the door to open? (1 per door)