In the 16.0 Enforce console, open Manage > Discover Scanning > Discover Targets.
If you have multiple targets with a common keyword, you cannot select that keyword when using a Custom Filter.
You must enter or select the full target name, one at a time.
The Custom Filter only allows "=", it does not allow "including" or "contains".
So each discover target must be selected individually.
If a business unit has hundreds of discover targets, they cannot select all of them at once.
They can only select one at a time.
Whereas, in 15.8, you can select multiple targets just by searching for a keyword, the department (business unit) identifier in this case.
A Feature Request has been submitted to the Product Manager to add "contains" or "includes to the custom filters list of operators.
If you want your account added to this Feature Request, open a support case and provide the engineer with this KB number.