I presume you mean showing a value for "January" containing January's data, summed;
a value for "February" showing January-February data, summed;
a value for "March" showing January-March data, summed; etc.
Is this right?
What sort of visualisation do you anticipate? Do you want to filter data and see it update?

As an example - a single report showing the following columns of data by whatever filtering is used:(product sets, divisions etc)

A column for £ and one for customer number with the ability to perform calculations such as customer yield:
covering:
Month actuals
YTD actuals
Prior year month actuals
Prior year YTD actuals

I'm afraid this scenario requires two features not yet present in Omniscope.

1. You need a formula function to calculate running totals, so you can calculate YTD.
2. You need to be able to enable calculation of formulas upon the view's data subset (currently formulas are unaffected by filtering, and are calculated for all data), to enable the YTD values to update when you filter.

This has been requested by other clients, so is likely to be developed for Omniscope 2.6. If you need this feature more urgently please contact Visokio.