find_ancestor_cgrp_ctx
cgc = find_ancestor_cgrp_ctx(cgrp, level);
pcgc = find_ancestor_cgrp_ctx(cgrp, level - 1);
cgc = find_ancestor_cgrp_ctx(cgrp, level);
pcgc = find_ancestor_cgrp_ctx(cgrp, level - 1);
pcgc = find_ancestor_cgrp_ctx(cgrp, cgrp->level - 1);