How do I track the work that team members do for creating the epics, sub-epics?

I started a new group for a contract that lasts several years. The initial epics and milestones (about 20 of them) were listed in a contract document and I have entered them at the group level. Now I want to assign issues to individual SMEs for breaking down the epics into sub-epics and eventual project creations. But there are no issues at the group level for doing group level things. I would like to show the assignments in a kanban. The only thing I could think to do is make an “Epic Planning” project that only has group level tasks/issues (no actual code or documents). Is this my only choice?