private HashMap<Long, String> map_one = new HashMap();
private HashMap<Long, String> map_two = new HashMap();

public void SynchMethod {
      ....тут какой-то код 
            synchronized (map_one) {
                synchronized (map_two) {
                    try {
                        map_one.put(1L, "some text");
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
    }

synchronized (object1) {
   synchronized (object2)  {
      synchronized (object3)  {
         synchronized (object4)  {
         }
      }
   }
}

get() -> read HashMapOne
add() -> add to HashMapOne
remove() -> remove from HashMapOne
validate() -> read HashMapOne AND add to HashMapTwo
check() -> remove from HashMapTwo

public class ShowClass {
    private static HashMap<Long, String> hashMapOne = new HashMap<>();
    private static HashMap<Long, String> hashMapTwo = new HashMap<>();
    
    public static void get(Long id) {
        synchronized(hashMapOne){
            if(hashMapOne.containsKey(id)){
                System.out.println("Exist");
            }
        }
    }
    
    public static void add(Long cid) {
        synchronized(hashMapOne){
            hashMapOne.put(1L, "Some text");
        }
    }
    
    
    public static void validate(Long id) {
        synchronized(hashMapOne){
            synchronized(hashMapTwo){
                if(hashMapOne.containsKey(id) && !hashMapTwo.containsKey(id)){
                    hashMapTwo.put(id, "Some text");
                }
            }
        }
    }
    
    public static void remove(Long cid) {
        synchronized(hashMapOne){
            hashMapOne.remove(cid);
        }
    }
    
    public static void check(Long id) {
        synchronized(hashMapTwo){
            if(hashMapTwo.containsKey(id)){
                hashMapTwo.remove(id);
            }
        }
    }
}

public class ShowClass {
    private static HashMap<Long, Pair<String,String>> hashMap = new HashMap<>();
    ....
}