How can we get the Child processInstanceId as i have 1 parent process but i need to find all the childs associated with That parent , how can i get it through Query / or any code need to write in java to achieve it , thanks

How can we get the Child processInstanceId as i have 1 parent process but i need to find all the Childs associated with That parent , how can i get it through Query / or any code need to write in java to achieve it , thanks