same contact list but need to filter and control access to leads, etc

same contact list but need to filter and control access to leads, etc


Just started using CRM - so far I like it and it's integration with the business suite.  I called customer service to ask this, and was told someone would call me not today (Friday) but not until Monday...hmmm
 
Anyhow, I represent several different companies.  I need separate "accounts" for each of them, but using the same contacts.  For instance, someone I meet at a conference may be a lead for three different opportunities with three different companies.  I don't want the companies to see all the other unrelated stuff - I want to allow them access as users, but I want to filter the data they have access to.
 
I upgraded to the most expensive package thinking the "groups" feature would help me, but it doesn't seem to.  Any ideas on how I can manage this?  The only option I see now is to not give them access, but just them reports - and actually, I am not even sure this would work.
 
The more I think about it, the more I think I simply will not be able to allow them access - oh well.
 
Thanks,
E