Disclosures: Explore patterns for handling nested selection

Problem to solve

In some cases there are many actions that can relate to a single item, and some of those actions may be related, such as multiple copy actions. In other cases it may be helpful to show secondary selectors as part of the action selection, for instance showing users available types when using "Change type" would help clarify what this action does — you can immediately see what choices it affords you.

Other consideration

There are also cases where users need to select a value from with a grouping of values, such as project from within a group. See #3259 for exploration of this use case.

Example

One immediate place we could implement this is "Add related item", which could instead be "Add linked item > Related, Blocked, Blocking".

Summary: Allow users to easily browse actions and understand potential options for use (when relevant), while allowing for concise and meaningful IA decisions within the menu context

Alternate keywords for searching: nesting, multistep, multi-step, parent child, hierarchical, progressive disclosure