  We present homogeneous Yang-Baxter deformations of the AdS$_5\times$S$^5$
supercoset sigma model as boundary conditions of a 4D Chern-Simons theory. We
first generalize the procedure for the 2D principal chiral model developed by
Delduc et al [arXiv:1909.13824] so as to reproduce the 2D symmetric coset sigma
model, and specify boundary conditions governing homogeneous Yang-Baxter
deformations. Then the conditions are applicable for the AdS$_5\times$S$^5$
supercoset sigma model case as well. In addition, homogeneous bi-Yang-Baxter
deformation is also discussed.
