Biomolecular condensates, often formed by liquid–liquid phase separation into coacervates, play a central role in organizing cellular biochemistry. These condensates can adopt multiphase architectures, raising fundamental questions about how their morphology and interactions are controlled. We examine this phenomenon using a theoretical framework that describes how surface-active molecules modulate wetting transitions in multiphase coacervates. Our model shows that increasing interfacial protein concentration drives a shift from fully nested to partially wetted architectures. This transition creates exposed coacervate cores that adhere into chain-like assemblies, stabilized by surface tension and resembling semiflexible polymers. The theory captures how local interfacial activity can regulate large-scale organization, providing a general mechanism by which cells may control condensate morphology and connectivity.