A. Create individual field contexts for each issue type.
Label the Due Date field as Join Date and Leave Date in their respective contexts.
Associate each context with its matching issue type.

B. Create individual Join Date and Leave Date custom fields to replace the Due Date field.
Create separate screens for each issue operation and issue type.
Delete the Due Date field.

C. Create individual Join Date and Leave Date custom fields to replace the Due Date field.
Appropriately migrate existing data from the Due Date field to the new custom fields.
Remove the Due Date field from all project screens.

D. Rename the Due Date field to Join Date and create a separate Leave Date custom field.
Create new screens for the Leave issue type and replace the Due Date field with the newly created field.
Migrate existing field values to the new Leave Date field.