How to map a "Dynamic Choice List"(DCL) field Value to a "Text" Field in Custom Object

In our custom object Project Closure, we have a Dynamic Choice List (DCL) field called Project Name, which is related to the standard 'Project' object and displays the 'project names' for selection.

When a user selects a project Name from this DCL during form creation, we want to automatically populate other fields like:
1. Project Manager Name (Text field)
2. Project ID (Text field)

These fields should pull data from the selected project record. The purpose is to make data entry easier and avoid manual input.