As a ABC user, I want to generate report that includes only the flagged internal "Work Notes" field

[AmrutaP79040408]

Requirement: Reporting on Flagged Internal Work Notes
Background

As an ABC user, I need to generate a report that includes only the flagged internal “Work Notes” from the activity log. The objective is to efficiently extract and report on the relevant portions of the activity history that have been specifically flagged.

In the Legal Workspace, we have a Work Notes section within the activity stream. The requirement is to identify only those Work Notes that have been flagged and make them available for reporting.

What I Have Identified So Far

I investigated where the flagged Work Notes are stored and found that the information appears to be maintained in the sys_activity_supplemental table.

Within the payload field, the flagged entries contain information similar to:

"api_version":"1",
"flag":true

The supplemental record also contains:

Event ID – contains the sys_id of the journal entry.
Document ID – corresponds to the element_id in the sys_journal_field table.

Based on this relationship, the data flow appears to be:

sys_activity_supplemental → Event ID → Journal Entry (sys_journal_field)

and

sys_activity_supplemental → Document ID → sys_journal_field.element_id

This allows us to identify the corresponding journal entry and determine whether the Work Note has been flagged.

Current Challenge

The main challenge is that I cannot directly create a report on this tables using the relationship between sys_activity_supplemental and sys_journal_field.

I was able to achieve the requirement by creating a custom table and bringing the required information into that table. However, I would prefer not to use a custom table if there is an out-of-the-box or more maintainable approach.

Approaches I Would Like to Explore

I am looking for recommendations on whether there is an existing platform capability or alternative approach that can be used to:

Identify/fetch only the flagged Work Notes.
Establish the relationship between sys_activity_supplemental and sys_journal_field.
Make the flagged Work Notes available for reporting without creating a custom table.
Also ****
Additional Requirement

There is also a broader requirement beyond Work Notes.

We would like to understand whether the activity stream can be used to extract/report on other types of activity, such as:

Additional Comments
Emails
Attachments
Other activity-stream entries/events

The goal is to determine whether these different activity types can be extracted and presented in a report in a similar way, preferably while retaining the relationship to the underlying record and activity/event.

Has anyone implemented a similar requirement in Workspace or the Activity Stream?

Specifically, I would appreciate guidance on:

How to report only flagged Work Notes.
Whether there is an OOB approach that avoids creating a custom table.
Whether a Database View could be used for this purpose. I understand that this approach may have potential performance implications, but I would still like to explore whether it is a feasible option.
Whether the same approach can be extended to attachments, emails, additional comments, and other activity-stream entries.
Any limitations or considerations around reporting directly from sys_activity_supplemental and sys_journal_field.

I have also attached a screenshot for reference showing the activity information we are trying to extract.

Any suggestions, documentation, or examples of how others have approached this would be greatly appreciated.