Concur may have the feature to enable you to specify quiet tightly which flight times and arrival/departure airports you will use, and maximum connection numbers and durations. This can result in a pretty chunky economy fare.

As you clearly know, being flexible with start/end points and a willingness to connect can result in low premium/business fares. A willingness from your employer to allow ‘working from lounge’ can also help no end if leaving a day early is the key to a much lower fare. But the single best way to avoid higher business fares is to book a long way in advance - and most actual business travel isn’t planned that way unfortunately.

As others have advised, speak to colleagues and find out what the custom and practice is.