It could also mean to discuss something philosophically

Exactly! You better provide some context to denote the exact meaning conveyed in the text. It could be 'a higher level' of precision ,intricacy or a level where more details and information is conveyed or a more sophisticated level discussing more difficult issues. It depends entirely on the setup,it could also mean to take it to a higher level of management in a certain hierarchy or to a higher level of confidentiality,where there is discretion in keeping information.

It depends on the context; Let us talk about something more complex and less basic. Let us talk about something that is more polite and not so crude. Let us talk about something that is more spiritual and less ordinary. Any of these might fit, depending on the context.