Add descriptive flexfield to list view

Summary:

Add descriptive flexfield to List View

Content (required):

I enabled a flexfield for expense items, and that is working. I'd like to add the flexfield to the Available Expense Items list view. I created a sandbox with page composer enabled. I tried to edit the page, but I can't select the list no matter what I try. Is there a trick to selecting the list for editing, or do I need to go somewhere else to edit the list view?

Version (include the version you are using, if applicable):

23A

Code Snippet (add any code snippets that support your topic, if applicable):