How to link employee data model to new requisition for which they have applied

Summary:

Content (please ensure you mask any confidential information):

We have job offer letter data model from which we fetch the offer letter template report.

Now we are creating a new offer letter for internal candidates , so that when they apply for a new position internally and we can create a offer letter for them using the same data model. But we not sure how we can map/link the existing employee data to that of the offer letter data model.

Version (include the version you are using, if applicable):

23c

Code Snippet (add any code snippets that support your topic, if applicable):