Customized View available fields

Good Morning Guys,

I'm trying to elaborate a customized view (for a To Do List) to use it as a standard for our "Service Managers".
My goal is to create a view that must contain few key information such as "ticket" ID, Status, Assigment Group, Target Date and Module and it should contain together incident and service request records (without change or release ones).

I can't find a way to expand the range of fields on whitch I can set my filter.

For example, if i start from a "to do list" and I try to customize it, i can only set my filter on few attributes of the incident or service request (such as ID, Status or Targert Date) but other attributes (such as Category or Subcategory) are not displayed in the filter menu to be used.

There's a way to add other fields and make them available in order to refine my view?

Thank You for your help.