Member-selection diagnostics for group ID 4. Left: redshift distribution of AMICO candidates. The red solid line and hatched region (bounded by green lines) represent z_DET and the adopted selection window Δz = ±0.01(1 + z_DET), respectively. Middle: projected distribution of LTGs (blue) and ETGs (red) in concentric annuli, with galaxies having assoc_prob > 0.5 shown as filled circles and those with assoc_prob ≤ 0.5 as unfilled circles; matched HLAGN are marked as stars colored by |z_AGN − z_DET|. Right: radial surface density profile showing ETG, LTG, and combined overdensities after subtracting the local background (PER). Panels in the bottom row repeat the analysis for high field-probability galaxies (e.g., FIELD_PROB > 0.7). Negative values indicate underdensities, where the accumulated density minus the outskirts baseline becomes negative.