The "Allow display of scenario-specific cash flows" setting enables you to use return scenarios within the Retirement > Cash Flows tab of a client plan. Return scenarios are RightCapital's way of giving you granular control over sequence of return within your client plans.
To turn on return scenarios within the Cash Flows, navigate to the Gear Icon > Settings > Methodology page, and check the 'Allow display of scenario-specific cash flows' setting:
This will allow you to view that client's cash flows in the context of the four default return scenarios, as well as any of your own custom return scenarios.
If you'd like for this setting to be enabled by default for all new client plans that you create going forward, you can check this same setting within the Advisor Portal > Client Settings > Client Presets tab: