Redshift distribution for the three initial sub-samples defined in Sect. 3.2. The samples of field galaxies (grey area) and galaxies in small structures (dashed blue line) have relatively flat distributions. The peak of the distribution for galaxies in large structures (red line) is located at redshift z ∼ 0.7 and is driven by the largest structures (40 ≲ N ≲ 100) found in the COSMOS area of the MAGIC sample.