Unlink cascades in the same form

An issue we are facing is with the cascades, we have 2 consecutive and identical cascades in the form, one for the residence area and the other for the work area. The issue is that these 2 cascades seem to be linked somehow, whatever is selected in the first cascade is automatically selected in the second and the selection cannot be changed.
Any idea on how to unlink them?
Thank you

@mireillejazi, could you show a sample of how you have done it? Maybe the community should then be able to help you out.