I have a problem in javascript using regexExp

Question

I have this script

script = "%getUserID(%getUserID(%getUserId(Userid)))"

var regex = /%getUserID\((.*)\)/gi
var exec = regex.exec(script)
console.log(exec)

Output i get:

[
  '%getUserID(%getUserID(%getUserId(Userid)))',
  '%getUserID(%getUserId(Userid))',
  index: 1,
  input: '\n%getUserID(%getUserID(%getUserId(Userid)))\n',
  groups: undefined
]

Output i want:

[
  '%getUserID(%getUserID(%getUserId(Userid)))',
  '%getUserID(%getUserId(Userid))',
  '%getUserId(Userid)',
  'Userid'
  index: 1,
  input: '\n%getUserID(%getUserID(%getUserId(Userid)))\n',
  groups: undefined
]

I cant get the output i want, please help