Maps of EWs of the 2976 Mg II doublet line for all the detections found in the three fields analyzed in this work: PSZ1 G311.65−18.48 (top), RCS2 032727−132623 (center), and SGAS J1226+2152 (bottom). Both the image (observed) plane and the reconstructed absorber plane (dashed-line rectangle) are shown, with the crosses showing the positions of the three identified absorbing galaxies, referred to collectively as G1. In SGAS J1226+2152, the absorption on top of G1 is shown for completeness but not used in the analysis.