How to enhance Activity Search

Hi all,

I am currently trying to enhance the activity search by including additional search criteria. I created the structure CI_EEW_BUS2000126_SEARCH because it was not previously defined. I then added a new field (ZZACT_MGR) as BU_NAME1TX. I activated the structure but somehow I can't seem to find my newly created field on the list of available fields in the activity search page. Do I still need to do something with the structure?

P.S. I was able to enhance the account search page without any problems. In this case, the Customer Include structure was already created so I just added my new field to it.

I hope someone can help me with my problem. Thanks!