Filter for custom field values shows all options from all contexts

Summary

If a custom field is added to a Portfolio plan, the Portfolio filter will show all options from all contexts configured in the custom field in Jira.

Steps to Reproduce

1. Create a custom field with multiple contexts and values across contexts.
2. Assign different projects to separate contexts.
3. Load only one of the projects in a plan.

Expected Results

Only the field options in the context applied to the project should be visible.
Portfolio should identify the projects in plan (just like Agile boards identify projects in board) and only show the options defined in contexts used by those projects.

Actual Results

All options from all contexts are visible

Notes

This occurs because Portfolio doesn't check which projects are in the plan and thus, cannot limit the contexts it shows values from.

Workaround

No workaround is available.