Adding a new module (notes) for the timeline

[AJCH]

I've looked online to see if this is even possible in the CDS. But when you select yes to attachments and notes on a custom entity, it adds the the timeline to the main form, which allows you to add notes to the entity. That all works perfectly.

But I would like to know if there is a way for me to add additional options that users can add to that timeline? For example i wanted the user to add an Invoice to the timeline which would have different fields to the basic Note entity. 

I've added an attachment to showcase the exact area i'm talking about. 

[AJCH]

Still running into this error and I was looking over your comment and there is a key portion (I think) that is not visible in the new UI. 

Areas that display this entity

Any idea where this might be?

[AJCH · Accepted solution]

Ok I think I may have fixed it. 

You have to navigate to the back-end of the CDS:

1. Cog > Advance settings
2. Settings in the top left 
3. Under Customization select 'Solutions'
4. Select the 'Common Data Services Default Solution' from the list
5. On the left hand side select 'Entities'
6. Select the Entity you want your custom activity to show up on
7. Select Activities from under the Communication & Collaboration header. Save/publish
8. Now if you go back to your form in classic view
9. double click the timeline and you should be able to select activities as an option and select your custom activity. 

I'm not sure how you add a new note item, but I was able to add a new activity.