Looking at your documentation "Manage Epics on Agile Boards" (https://www.jetbrains.com/help/youtrack/standalone/Manage-Epics-on-Agile-Board.html) I would like to reproduce this setup however I encountered few issues.
I think I have understand the global setup :
1) one board deals with weekly sprints : User Stories as swimlanes and task/bug as cards
One board that use Quarterly Sprints and deals with Epics as swimlanes and User Stories as Cards
1) issue 1 : On my side, I have added quarterly sprints but these are visible on the executive board. I don't know how to only have them visibles on the Roadmap Board.
2) issue 2 : if I want to see my User Stories onto the Roadmap Board I need to assigned a Quarterly Sprint (Q2 2018 for example) to that user story which is complex as I already need to assigned weekly sprint on it. It is a twice sprint assignation
Thank you for yr help !
Best regards from france.