My interpretation is : (1) the subject is you wanted to change work (it can be employment or change to do something else) and (2) in the post you said you wanted to know where you could find a job for employment. Just clarify.
read the job advertisements and through words of mouth / friend's information. different headhunters deal with different industries and different seniority level of employment. also the headhunters will hunt you.
one more way is you have to make yourself known or you are one of the best in your field, somehow the anonymous huntheaders will find you somehow (they will not tell you from where or who they know about you and your telephone number). in my days, working in big corp has advantages in certain circumstances. some headhunters will just have trust in those worked in big corp as kind of quality control. suddenly, they would call your working phone to find you. in general, you must "package" yourself in present work properly as professional headhunters will do research on you (like we pick a stock) before they intorduce you to their clients, especially for senior management. if they are interested in you, they may even interview you in a posh restaurant (if you are not famous in the public). of course, these were old days, not sure about now.
one more way is you tell your friends that you are looking for a new job (spread your news out). you cannot believe many of your friends can help you through their other relationship. good luck.