Well with the viewpoint you can create new requirements attributes and then edit them from the tree view. Also, when you’re done with adding new attributes, you can also change how requirements labels are displayed in the tree view and also in diagrams (let me know if you’re looking how to do it and I’ll point you to the right entry points).
Please find below the steps that should enable you to create attributes to your requirements with the appropriate Data Types (like IE PUID, these data types are created automatically when importing from ReqIF files like the ones coming from Doors, but you can create your own ones).
If you have not already done it, create a “Capella Type Folder” (for instance right click on “System Analysis” folder ad you’ll find it), and name it “Types Folder” for instance
(Make sure these folders are visible in your project explorer and also all the requirements elements by changing the parameters in the customization view for your project explorer - un-tick the 3 Requirements artefacts in the list)
In your Type folder, create a “Data Type Definition”, and then in the property view, name it IE PUID for instance
In your Type folder, create a “Requirement Type”, and then in the property view, name it as you want, but this will be use to “type” your requirements (I used “MyReqType” in my example)
Inside this type, create a new “Attribute Definition”. In the property view, chose the Data Type “IE PUID” that you previously created and also name it IE PUID
Now take one of your requirements, and in the property view, choose the Type you created (MyReqType)
Inside your requirement, create a new “String value Attribute”, and then in the property view, choose the “IE PUID” as a Definition, and then give a value to your “String Value attribute” (I put MyValue in my example)
You should end up with something like this:
So this is how you can create these attributes and then edit them in the tree view.
I hope this helps.