You have to use Visualforce and a Controller to get the fields and parse into the knwoledge serach widget.
See some more related information in the link below,
It's possible to filter with Visual Workflow but you have to code that logic yourself (pass in an accountid as a parameter). In addition, UI functionality is currently lacking with flow. When you return multiple records that you want to take action on, you have to select one, take an action then select the next one. It's a slow process and can be time consuming to configure.
Visual Workflow is best used in conjuction with VF pages. The ideal use is: VF workflow contains the business logic, but the presentation layer is handled by a visualforce page.
You have to use Visualforce and a Controller to get the fields and parse into the knwoledge serach widget.
See some more related information in the link below,
It's possible to filter with Visual Workflow but you have to code that logic yourself (pass in an accountid as a parameter). In addition, UI functionality is currently lacking with flow. When you return multiple records that you want to take action on, you have to select one, take an action then select the next one. It's a slow process and can be time consuming to configure.
Visual Workflow is best used in conjuction with VF pages. The ideal use is: VF workflow contains the business logic, but the presentation layer is handled by a visualforce page.
https://success.salesforce.com/answers?id=90630000000h3ZWAAY
Regards,
Ashish