IBM Apptio

When you create a custom dimension, it asks what IT Planning tabs the new dimension applies to (Contracts, Labor, Assets, Other). What if later you change your mind and want to add the Dimension to additional tabs you didn't originally select? How do you do that? 

Scenario: I made a custom dimension called "ERP" and indicated it should apply to the CONTRACTS tab. Now we want to be able to tag things on the ASSETS and OTHER tab, and see all of the ERP inputs on the SUMMARY tab.

Steps taken to create the dimension in the first place:

1. Created ERP custom dimension, selected "Contracts" for applicable data. Uploaded ERP reference data. 
2. In Company Profile, I checked the box for "ERP" in the "Summarize financials by:" section (though this did nothing b/c ERP isn't on the SUMMARY tab.. but I did it anyways thinking it would bring ERP into the Summary tab) 

(Unsuccessful) Steps to add "ERP" to the Summary/OTHER/ASSETS tab:

1. I went to Schema>Financial Line Item>Add 
   1. I tried adding columns with the name "ERP" or "ERP Name" that are Lookup columns referencing "ERP" custom dimension. I got the following error both times "This attribute name is System Attribute / System Reserved Name / Duplicate. Please use another name".
2. So I tried changing the name to "ERP Tag", which did successfully add the column, but on the SUMMARY tab, it didn't summarize the "ERP" detail entered into the CONRACTS tab into the "ERP Tag" column on the Summary Tab.

So can you only add a Custom Dimension to a tab upon creation and never after?