I found a section of heritage permits that the Melbourne Metro Authority has applied for in order to make changes to the St Kilda Rd environs from Toorak Rd - past the current Domain interchange. The realignment of tramway tracks is central to this in order to provide room to construct the station along with the new Toorak Rd west line and the decommissioning of Domain Interchange in its current form. I've linked through the PDF file of the 5 constuction stages to construct the temporary tracks in St Kilda Rd. I would assume that once Domain Station is finished then the tram lines will resume running down the centre alignment. The changes are quite extensive and I can't adequately describe them here - you'd be best looking at the maps to see the scale of works. I can't recall a similar project that involves a temporary alignment of tram lines to this extent.