How to add Cost Center Manager in Approval?

Summary

How to add Cost Center Manager in Approval?

Content

Hi,

I've searched the forum for a bit on how to add the Cost Center Manager in the Expense Report approval flow.

I see there's a participant stating exactly that, approval by cost center, but by default it's ignored.

I've seen another topic which user the 'Resource' List Builder and then put in the following for 'User': Expense Report/costCenterTotalVO.Manager Username, but I'm not sure if it's correct since the flow wasn't working.

Is there any document or pointers you could give me on how to successfully add the Cost Center Manager to Expense Report Approval? (At this point just interested in adding him/her in, without any condition -> 1=1)