How to fetch values from different child tables of different parents

#1

Parent 1 = Travel Request
child 1 = Travel Itinerary [fields = travel_from, travel_to, mode, advance]

Parent 2 = Tour Claim
Child 2 = Journey Details [fields = travel_from, travel_to, mode, advance]

I want to fetch data from Travel Itinerary to Journey Details and fields are same as i mentioned above i tried but not succeed

#2

Got the solution

travel_request.py

@frappe.whitelist()
def get_journey_details(source_name, target_doc=None):
	doclist = get_mapped_doc("Travel Request", source_name, {
		"Travel Request" : {
				"doctype" : "Tour Claim",
				"validation" : {
				"docstatus" : ["=", 1]
				}
			},
			"Travel Itinerary" : {
				"doctype" : "Journey Details",
				"field_map" : [
					["travel_from", "travel_from"],
					["travel_to", "travel_to"],
					["mode_of_travel", "mode_of_travel"],
					["advance_amount", "advance_amount"]
				]
			} 
	}, target_doc)

	return doclist

tour_claim.js

frappe.ui.form.on(‘Tour Claim’, {
get_journey_details : function(frm,cdt, cdn){
erpnext.utils.map_current_doc({
method : “erpapp.travel.travel_request.get_journey_details”,
source_doctype : “Travel Request”,
target : frm,
setters : [
{ label : “Employee Name”,
fieldname : “employee_name”,
fieldtype : “Data”

				}
			],
			get_query_filters: {

				docstatus : 1

			}
		})
	},
});