"Public" role using Row-Level Security

It sounds like two reports in the way to go: I'll need a PublicReport and an OrganizationalReport. 

There are a mulitple data sources feeding these reports. It seems like it should be possible to create duplicate datasets for each data source (one public and one organizational for each data source), and then build the PublicReport and OrganizationalReport off of these. 

However, that seems unnecessarily duplicative--I want the initial work of importing/cleaning/etc. for each data source to happen once, not twice. For example, if I load a table from a spreadsheet,  I want that to happen in a single query--I don't want one query to load that data for later use by the PublicReport and a totally seperate query to load that same data for later use by the OrganizationalReport. 

Is there a way to split these two strands of data AFTER each data source is loaded cleaned (and potentially combined into a MasterDataSet)....or do I need two seperate datasets for each data sources?