const regex = /(\(.*?\))((([\w ]+)?\()+)?/gi;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(\\(.*?\\))((([\\w ]+)?\\()+)?', 'gi')
const str = `asd (sad)yuuy(asd) () (asda(s(asdasd)asd(asd)d))
(ads (sygyg)iuiuiu(as (as (asd)sad(sadasd)(sad)d)asd(as)asd))
lnh(Ly(u)hO)GbCGfBzOKtp kSMS( n(d)L z(v( K)U) w)haMDJjjdEjIVd(I)gWFpKVajcsLcuJA
// lnhGbCGfBzOKtp kSMShaMDJjjdEjIVdgWFpKVajcsLcuJA
Cbup((AyW)dA(E)f((B) (HhQz (ZQ(z )QSd )Aq)r(bws ) Koza(tXn)n(uk)J)a) (lJ(u(W o)h w)spy(i(Ry)qkKANk))(d)YJ(W)(LpTwt)E()
// CbupYJE
YbTc (P(FCDZwe))yqF(CB(ooH)Jw(rc)lHrpR)svHi(AZ)Uqd(n hhmk( S B )yqTLJ(TI(vf)deG m)Lt)stZmYMmDio(y Lfpd)y(uAoAHy)CVKd(gFc w)q(CSd (DUqZg)XAHa)SH
// YbTc yqFsvHiUqdstZmYMmDioyCVKdqSH`;
const subst = ``;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions