I'm hoping there's a solution now for this too, but the last time I checked this with LANDesk the response I had back is that this is unavoidable, at least on the query prompts. Apparently this is due to support, supplier and customer groups all living under the 'Group' object so they're all displayed on the prompts with no way to filter what's displayed there - unless something has changed recently that now allows this in 7.4?
As Darren has pointed out, this is how it is meant to function. The Query will show you everything in the Group table which Support Group, Customers, Supplier and Company all belongs to.
There is currently an enhancement request for this which you can vote on if you would like this feature to change:
I will vote on the enhancement. Has to be a Functional over site here I am thinking. I am sure that no one would ever want all group types to display on a workload list query prompt but correct me if I am wrong? This will be extremely messy in version 74 since service catalogue requires you to use company (Division) and customer groups (Departments) if you want to publish services respectively.