Displaying Related Collection and Subcollection Data in a DataTable

I currently have a structure where I can select a user and retrieve their information in a DataTable widget. However, I would like to extend this functionality by associating it with a subcollection that stores the user's attendance records. Specifically, I need to display today's attendance for each user within the same DataTable.

Currently, my structure is as shown in the attached image. I would like to understand how to properly fetch and display data from both the main collection (users) and its subcollections (attendances) for each document.

Key Requirements:

The DataTable widget must be used because it provides essential features like pagination, user selection, sorting, and filtering.
I do not want to use ListView, custom-built columns, or manually structured layouts—it must be implemented directly in a DataTable.
The solution should efficiently retrieve and associate the user's attendance record (specifically, today’s attendance) alongside their existing user data.

Manual Table with Dynamic Queries
- I created a table manually, adding columns and using dynamic generate query for each.
- On the main page, I added an action to load the queries from the necessary collections.
- However, I don’t want to use this approach since I need the integrated DataTable widget, which includes pagination, record selection, and built-in features.
Fetching Data from Collection and Subcollection
- I successfully retrieved queries for both the main collection and its subcollection and displayed them in a column. (But not in a Datatable widget)
- However, I can’t establish relationships between the data (e.g., linking attendance status to the correct user or date).

I would like to know how to properly relate subcollection data with its parent collection inside a DataTable widget.