Not sure what element it is, but I think there is some element for a step in width that has an additional offset, so that you can move the narrow line to the edge of the wide line.
I would use Momentum, because these elements assembled from many small layout blocks can have much parasitic coupling between the blocks. Don't expect too much accuracy from schematic models for this type of layout. Momentum is much better for this.
This appnote might help you with scalable layouts in Momentum:
https://muehlhaus.com/support/ads-application-notes/em-parameters-momentum