ParseCustomerJourneyWorkflow.js

Xrm.WebApi.retrieveRecord(
    "msdyncrm_customerjourney",
    "945a02a0-b2db-e811-a967-000d3af29269",
    "$select=msdyncrm_workflowdefinition").then(
    function (result) {
        debugger;
        console.log(result);
        var workflowdefinition = JSON.parse(result.msdyncrm_workflowdefinition);

        // Retrieve nodes related to provided component.
        var emails = rootActivityFilter(workflowdefinition, "Email");
        var segemnts = rootActivityFilter(workflowdefinition, "Segment");
        var events = rootActivityFilter(workflowdefinition, "Event");

        // To get all the record's GUID & metadata use .toArray()
        var emailRecords = emails.where(x => x[0].ItemId != null).toArray();

        // If you want just number of records .count() can be used
        var eventCount = events.where(x => x[0].ItemId != null).count();
    },
    function (error) {
        console.log(error.message);
    }
);

// funtion to filter out only data node for provided element
function rootActivityFilter(workflowdefinition, element) {
    return Enumerable
        .from(workflowdefinition)
        .where(w => w.ActivityTypeId == element)
        .select(s => s.Properties.Items);
}