Employee rate based on dependent count

Summary:

I have a requirement to populate employee rate based on the dependent count. we can use Rate value calculation fastformula to achieve this. However, we have to use this formula only for "Post enrollment calculation" method and if we follow this approach Employee can only see the employee cost after the submission of the enrollment. My requirement is while employee designating the dependent then just after clicking on continue button just before submit system should show the employee cost. Can we achieve this via any other configuration.

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