public class MyQueueable1 implements Queueable {

     Public Static list < Account > acclist = new list < Account > ();
        public MyQueueable1() {

        }
        public void execute(QueueableContext context) {

            System.enqueueJob(new MyQueueable2());
        }
       //This class is not executing..
        public class MyQueueable2 implements Queueable {

            public MyQueueable2() {

            }
            public void execute(QueueableContext context) {
                List < Account > a = [SELECT Id, Name
                                      FROM Account WHERE Id =: acclist];
            }
        }
    }

public abstract class ChainedQueueable implements Queueable {

    private Set<Id> recordIds;

    public AbstractChainedQueueable(Set<Id> recordIds) {
        this.recordIds = recordIds;
    }

    public abstract void processRecord(Id recordId);

    public abstract ChainedQueueable createJob(Set<Id> ids);

    public void execute(QueueableContext context) {

        if (recordIds.size() == 0) {
            return;
        }

        Id recordId = getNextInvoiceId();

        processRecord(recordId);

        processNextInvoice();
    }

    private void processNextInvoice()
    {
        enqueueJob(this.recordIds);
    }

    private void enqueueJob(Set<Id> ids) {

        if (ids.size() == 0) {
            return;
        }

        // create next job
        AbstractChainedQueueable job = createJob(ids);

        // queue next job
        Id jobId = System.enqueueJob(job);

        System.debug(jobId);
    }

    public void enqueueJob() {

        // queue job
        Id jobId = System.enqueueJob(this);

        System.debug(jobId);
    }

    private Id getNextInvoiceId() {

        // get next record
        Id recordId;
        for(Id item : recordIds) {
            recordId = item;
            break;
        }

        // remove recordId
        recordIds.remove(recordId);

        return recordId;
    }
}

public class ExampleChainedQueueable extends ChainedQueueable {

    public ExampleChainedQueueable(Set<Id> recordIds) {
        super(recordIds);
    }

    public override void processRecord(Id recordId) {
        // do work here
    }

    public override ChainedQueueable createJob(Set<Id> ids) {
        return new ExampleQueueable(ids);
    }
}

Set<Id> recordIds = new Set<Id>();
new ExampleChainedQueueable(recordIds).enqueueJob();