[Backend] Spike: MVC: Investigate requirements and current filtering capabilities

We should use this issue to:

• Engage with Design: MVC: Filtering and Sorting for Group-le... (#515955 - closed) • Michael Fangman • 18.3
• Determine the backend requirements
  • What filters will be needed
  • How should they work, etc.
• Determine if any of those backend requirements are already met
  • It's possible some filters, Group based filters for example, are already supported
• Determine what backend work needs to be done to meet the requirements