Thank you Don Yang. I found a better option to "Archive" the value need to hide from the list. this will not show it again in the list and avoid showing literal id. it instead shows the same value but say that it is not applicable so give me option to select a new value for it. So this is better than removing it.

Thank you again.

You are right, Archive the value can be a better option for the end users as the impact to them is that they may not really notice the backend change you have made. From business of view, as the value is no longer valid, you would expect the users to manually change the value. For those users who only have the new value list(for selection), when they view the workitems with the archived value, they may feel confused where the value is from if they don't know the history. Sometimes it is a dilemma. But if that is suitable option for your scenario, that's good to know. I think there is reason the tool provides both "delete" and "archive" options for different use cases.