how to retrieve initially loaded data from data table after filter
if you mean unfiltered data then table.serialize(true);
https://docs.webix.com/api__link__ui.datatable_serialize.html
all:boolean
argument is not documented though
you can use dt.filter()
to reset a widget back to the initial state
also, there is a serialize API, if you need to get the data only
https://docs.webix.com/api__link__ui.proto_serialize.html