How we can migrate DXL scripts from DOORS to DOORS Next

Accepted answer

Short answer: You can't. DXL is a DOORS-only language.
Slightly longer answer: You might be able to replicate some of the functionality using the DOORS Next JavaScript scripting capability, but it will mean recoding rather than converting. The basic concepts are too different to allow a simple translation. Take a look here: https://jazz.net/wiki/bin/view/Main/RMExtensionsMain