Helpdesk - Assignment rules based on Sub category but with access to category's queues

Summary:

Requirement:

On the automatic routing. Can some SRs be routed to a queue and then subcategories go to a specific person or multiple people within a queue?

Example: For Benefits, we may have 4 people in that queue. But 401K questions go to one person, dental insurance goes to another person. Is it able to get that granular based on how we set up the categories & subcategories?

Also, when it comes to searching for previous SRs. Are all of the agents able to search and find any of the previous SRs, if they are searching by a specific person or