Can the following action be performed using Rapid Setup application onboarding?

Rapid Setup does allow for specifying account correlation by mapping an identity attribute to an account attribute. This is a standard part of the onboarding process where you define how IdentityIQ should correlate accounts to identities. This basic mapping functionality is included in Rapid Setup to facilitate straightforward account correlation during application onboarding.

SailPoint IdentityIQ Rapid Setup Guide

SailPoint IdentityIQ Administration Guide (Account Correlation and Mapping Sections)