Is there a way to customize the standard fields in expenses?

Summary:

is there a way to customize the standard fields? like in the below screen, if the flight duration (this is a free text) is < 3 hours, then in flight class only Economy should show. If the flight duration is >3 hours then both Economy and Business class should show up. How can this be achieved ?

Content (please ensure you mask any confidential information):

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

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