new custom fields to Standard Worklist freight orders

Hello experts,

I go to you asking for help, we as a development team are kinda newbies in the TM box, and we are in the middle of a TM Implementation, our requirement is to add several custom fields for the standard worklist for freight orders, we already enhanced the freight order object and added the new fields to the root node, actualy we already add the fields to the freight order management screen:

But that is just the half of the requirement, the second part is to add these fields to the corresponding result for the worklist "all freight orders":

Following the SAP Transportation Management 9.X Enhancement Guide, (we are implementing SAP TM 9.1) I came to find that I need to add the fields to a object query, update a feeder class and enhance the worklist, but here's where the problem begins, and my questions rise:

where can I see which worklist or query do I need to enhance? I tried using the buttons with the wrench in it, but couldn't find it.

Is there any step by step tutorial for this matter? what if I need to enhance any other worklist?

as of now we are still stuck in getting the correct worklist to enhance.

all help would be appreciated and rewarded.

Thanks!