Expanded swimlanes for work item boards
## Summary
Users can currently configure board lists (columns) on GitLab by selecting fields such as labels, assignees, milestones, and iterations. Although the current grouping options make arranging and viewing issues or epics powerful, issue boards are still limited to a single horizontal grouping option, by epics.
We plan to expand this horizontal grouping, by offering it for both issue and epic boards. Additionally, we will provide users with the ability to group by a wider range of fields, enhancing their board customization options and streamlining their workflow.
This feature enhancement will greatly improve user efficiency by providing improved access to information without having to open multiple tabs or create multiple boards. We expect this will greatly improve the efficiency of collaboration, particularly in team standup meetings.
### User Persona
This enhancement is relevant to a range of GitLab users, including Product Managers ([Parker](https://about.gitlab.com/handbook/product/personas/#parker-product-manager)), Development Leads ([Delaney](https://about.gitlab.com/handbook/product/personas/#delaney-development-team-lead)), Developers ([Sasha](https://about.gitlab.com/handbook/product/personas/#sasha-software-developer)), and UX Designers ([Presley](https://about.gitlab.com/handbook/product/personas/#presley-product-designer)).
## Proposal
Horizontal swimlanes for:
* Parent (change existing "epic" to parent, allows for grouping tasks by issues, and subepics by parent epic)
* Health status
* Assignees (with selector)
* Labels (with selector)
* Milestones
* Iterations
* Work Item Type
* Custom field (with selector)
* Custom status
* Projects (with selector)
* Subgroups (with selector)
epic