When using Custodian Manager to select custodians to be searched, all Custodians that were active during the search date span (and Custodian Groups) are available to all cases and research folders within DA. Individual Custodians or Custodian Groups cannot be designated for use only by specific persons or groups.
What you CAN do to approach the granularity of control that you want is to create a new case for the limited research folder. Within the new case, you can create Targets that are only available to that case. Those Targets can be placed into Target Groups that are also only available for use within that case. Each Target would need to be populated with the name, SMPT address(es) and Display Name(s) associated to the person to be used in the searches. Once this is all populated, you can then create a research folder that is a child of that case and let the Group 2 folks run searches in that research folder.
This would still provide them with the ability to choose any Custodian or Custodian Group from within Custodian Manager, though. Their search criteria would need to be checked to confirm they only select people to be searched that have 'T:' or 'TG:' before their names to confirm they are only using Targets or Target Groups. Any person to be searched that has 'C:' or 'CG:' before their name would be a Custodian or Custodian Group. To elimiate their ability to access Custodian Manager, you would need to install a new instance of DA on a separate DA server, using a separate DA Configuration database and no Custodian Manager customer. That would mean Group 2 has their own DA server with their own DA Customer in which you can create application level Targets that can be used within any case or research folder.
Setting up a second DA server with its own configuration database, customer, Targets and Target Groups is a lot of work, but it would provide the granularity that you want.
