X-ray luminosity functions in two different redshift bins (z ∼ 2.2 and z ∼ 3.2) and in luminosity bins of 0.5 dex. Our data are shown as cyan and green points, with different markers representing different assumptions on the co-moving volume. For comparison, XLFs for the field environment at similar redshifts are also reported. The solid purple line shows the XLF for field AGN from Gilli et al. (2007). The dashed lines correspond to the XLFs from Ueda et al. (2014) at z ∼ 2.2 and z ∼ 3.2. The dotted line shows the XLF from Georgakakis et al. (2015), and the purple shaded area represents the XLF estimated by Vito et al. (2018b).