Create new Custom Field that should be available for Activity Header and Knowledge Article Search Views

Hi Experts,

I have to created with the AET a field that was added to the header of an Activity and the header of a Knowledge Article. I have used the object BTADMINH to create the field.

I have made in the AET this field search and result relevant BUT as I now found out, this field is not available as a search field in the knowledge article search component  CRM_KNOWART_S !

Do I have to do coding or do I have to create the field by using the object CustomerH?

How in general I can check, when creating a new attribute where this attribute will be available (in which components) ? Is there a way?

Thank you very much.