How to make Project number and Task Number based on the business unit

Summary:

we have requirement while creating the Project billing events for some of the Bunises units project number and tsk number should mark as Optional and rest of other business it should be required .

Customer option by using the page composer options but it making the project number and task number optional for all business units

Content (required):

Manage Events

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

22D

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

Enable the sandbox, go to Manage event page -> Click on + Icon

Enter all Mandatory values Business unit , contract , contract line number , contract type , organization , project number and task number now ,edit the sandbox for edit and go the properties of Project number , under required option expression builder , choose bind param as Business unit and past below