google-analytics - How link multiple dimensions

Question

I am trying to pull data for below fields with ETL and build a custom report. I can pull at max only 7 fields using ETL (Pentaho PDI) at a time. Is there a way to link these dimensions (User, Traffic Sources, Geo Netwrok) using a unique key like Surrogate Key after extracting data? Thanks in advance.

ga:source        <-User
ga:sourceMedium  <-User
ga:userType      <-User
ga:sessionCount  <-User
ga:campaign         <-Traffic Sources
ga:adDestinationUrl <-Traffic Sources
ga:keyword          <-Traffic Sources
ga:city            <-Geo Network 
ga:userAgeBracket  <-Audience