The vega result displays the change in the instrument’s value for a 1% change in the volatility based on the ATM volatility.
You can also view the vega per tenor, i.e., see the sensitivity of a specific tenor to a 1 basis point shift, in the Single Option page for some instruments via the Vega Buckets window (this is accessed by clicking the Vega Buckets button). Alternatively, in the Portfolio page you can see the vega per tenor via the Risk Matrix tool.
For use in the Risk Matrix tool and the Vega Buckets window you can change the default definition of this Greek. You do this in the Settings window > Greeks tab. For more information see Customizing the Greeks Calculations.