Merge 2 adjacent Sentinel-1 Swaths

Dear all,

I am trying to merge two adjacent Sentinel-1 images (Swaths) into 1. I know it is possible to do so when the two images pertains to the same track using the Slice Assembly. I also know it would be possible to merge different sub-swaths using Merge. However, in my case, I need to merge two different swaths (from 2 different traks) with are laterally overlapping as in the screenshot here attached.

overlap

I need to perform this prior or just after the interferogram formation since then I would compute the unwrapping phase and all the other steps to obtain LOS maps.

Is there any solution to do so?