"在那个场合下" can be translated into English as "in that situation" or "under those circumstances", depending on the context.
"In that situation" is more general and can be used in various contexts to refer to a specific setting or occasion.
"Under those circumstances" emphasizes the conditions or factors surrounding the event, which might be more appropriate when discussing the environment or context in detail.
For example:
In that situation, I had no choice but to speak up.
Under those circumstances, it was difficult to remain calm.