Large-scale structure of the overdense environment in the GOODS-N field at z = 5.17 − 5.40. Galaxy positions are shown relative to HDF850.1, in units of comoving Mpc. All galaxies are colour-coded by redshift. The eight N2CLS galaxies are indicated by crosses (for spectroscopic redshifts, z_spec) and upward pointing triangles (for photometric redshifts, z_phot); their NIKA2 identifiers are labelled in red, with source 20 discussed in Appendix D. Galaxy groups and filaments are taken from the JADES survey (Sun et al. 2024), with galaxies in less dense regions shown as transparent symbols. Additional galaxies, shown as dots, are drawn from the FRESCO survey (Herard-Demanche et al. 2025).