You want to hide Edit or sub-menu available in Action button within campaign screen.
HTML5 & Fiori
Reproducing the Issue
Go to the Sales Campaign Work Center.
Click on Campaigns view.
Open any Campaign.
Click on Adapt and then Edit Master Layout.
When you hover on Edit / Actions, there is no option to make this hidden.
This is expected behaviour. Currently hiding is not possible for these button group within Campaign screen.
This feature is added in development backlog to be delivered in future releases.
KBA , campaigns ti , hide button , actions button , LOD-CRM-MKT-CAM , Campaigns , Product Enhancement