#include <pcre2.h>
int pcre2_set_parens_nest_limit(pcre2_compile_context *ccontext, uint32_t value);
This function sets, in a compile context, the maximum depth of nested parentheses in a pattern. The result is always zero.
There is a complete description of the PCRE2 native API in the pcre2api page and a description of the POSIX API in the pcre2posix page.