You could try using String#replaceAll
for a one-line solution:
String url = "https://example.com/?link=https://play.google.com/store/apps/details?id=com.example.cp&hl=es&apn=com.picker.cp&st=Share+this+app&utm_source=AndroidApp?businessId=5d8648b561abf51ff7a6c189";
String businessId = url.replaceAll(".*[&?]businessId=([^=?&]+)\\b.*", "$1");
System.out.println(businessId);
This prints:
5d8648b561abf51ff7a6c189
Actually Apache has a number of libraries that can make handling your requirement much easier. On Android, the following might work:
Uri uri = Uri.parse(url);
String linkParam = uri.getQueryParameter("link");
Uri uri2 = Uri.parse(linkParam);
String businessId = uri2.getQueryParameter("businessId");