Transitional Interfaces (TIs) in Extended Reality (XR) enable users to fluidly transition between real and virtual environments, offering new opportunities to ease collaborative tasks in shared physical spaces such as libraries. In collaborative environments where users operate across the reality-virtuality continuum, differences in perceptual context can create barriers to effective communication. This challenge is particularly pronounced in co-located scenarios. To address this, we developed a cross-reality application for Meta Quest headsets that uses various attention markers in TIs to help users coordinate object-finding tasks. A user study in a library evaluated the effectiveness of four markers: a Basic Marker for simple highlighting, a Pathfinding Marker that indicates a route, a Gaze-Adaptive Pathfinding Marker that aligns guidance with the user’s gaze, and a Funnel Marker that broadly directs attention based on gaze direction. The results indicate that attention markers enhance collaborative efficiency, minimize focus shifts, and improve overall usability. Among the tested approaches, pathfinding markers yielded the best performance, while gaze-adaptive variants provided additional support in maintaining user focus. These findings suggest that XR-based attention guidance can effectively mitigate perceptual discrepancies in co-located collaborative tasks.