Nexus Sprint planning participation

Perhaps it is a bit unclear written in the Nexus Guide but in the guide is also state that:

"The first part of cross-team Refinement should be spent decomposing Product Backlog items into enough detail in order to understand which teams might deliver them, and in what sequence over upcoming Sprints."

I would say before the Nexus Sprint Planning starts, the appropriate representatives from each Scrum Team comes together and validate and make adjustments to the ordering of the work as created during Refinement events.

Think of everyone as being there, and of the teams needing to self-organise so planning can be effective. To begin with, each team will need to self-organise its representation in establishing Product Backlog order. The most important step in planning at scale is to get integration dependencies under control and the ordering of work greatly influences this.

> I would say before the Nexus Sprint Planning starts, the appropriate representatives
> from each Scrum Team comes together and validate and make adjustments to the
> ordering of the work as created during Refinement events.

They might do that *as well*, during a further Refinement event (as the guide says, "At the scale of Nexus there are many levels of refinement"). However, the re-ordering and validation of work is also a specific activity to be conducted at the beginning of Nexus Sprint Planning, and as part of it. Getting dependencies under control is too important for this step to be elided. Clearly the more conscientiously Refinement is performed, the less controversial the order of work should be during Planning.

I think it's not complicated :-)

Here we can read: 

"Effective Nexus Sprint Planning occurs in 2 steps:

1. Each team in the Nexus selects their work for the Sprint. This is a collaborative activity with representation from each Scrum Team.

2. Each team performs their normal Sprint Planning process. This occurs per Scrum Team and can happen in parallel."