Having same id in collection giving me only one record i want all

i have a mongo collection on which i have my own defined exerciseMasterId but it have duplication but on return it is giving me only one record in three time as i want three record with three different name they have but it is showing me one and giving a console error

observe_sequence.js:6 duplicate id jdEKzpwsGsmc2Mr3S

please how i can print my each name