You can divide the database into sectors which can then be assigned to the consultants/users in order to exclude them from viewing records that are in a different sector.
To assign a user to a sector they don't have access to:
From the Ribbon, click Options then click Manager.
Click User Maintenance and double click on the user and their User Profile will appear.
Select the sectors that the user needs access to.
Once the above is done the user will need to:
Restart RDB.
From the Ribbon, click Options and then click Sectors.
Select the sectors that they need access to.
Click OK.