Job advertisement: "Liaise professionally"
This one is pretty easy. The requirement that you've mentioned simply asks for some proof, at least, informal one, that a person is capable to successfully facilitate professional interactions by communicating with people from various subject domains and convert ideas and information between domain "languages". In other words, successfully act as a subject domain translator.

The simplest example of such role from the industry would be a business analyst, which most often requires to translate requirements and other project information between business-focused groups and IT-focused ones. Roles of project / product / program manager are related, though different.

Therefore, to meet such requirement, which is very typical for both academia and industry due to their collaborative nature of work, I would say that listing successful projects (with specifying roles and relevant tasks &amp; achievements of facilitating interdisciplinary cooperation) in a CV is enough.