Join multiple Report Designer Queries

I have created several queries in the Pentaho reports designer which are listed in the Data Sets. I would like to join multiple queries into one so that I only have to create one subreport for all my data. I know that I can combine the queries using a UNION ALL operator, but the queries are quite large and I would prefer keeping them separated for data diagnostic purposes. Once a query is created in the reports designer, can that query be called 'similar to a view' from another query in reports designer? Query1: Select username from users; Query2: Select username from Query1 union all select username from masterusers;