How can I divide a metric from the current month between the previous month or the previous record in obiee 12c?
Have a look at the time series calculation functions, for example AGO(...) will let you access the previous month measure value.
The concept of "previous record" is very vague as a previous record always depend on the sorting applied to your analysis, so I would try to stick with something more defined like "previous month" (assuming you have a proper time dimension configured providing a clear definition of "previous month").
