Guide

Use the following code in the Custom Script section for whatever DocType.

The logic is that it will run the code when a search is done from the field, or when the field is selected.

frappe.ui.form.on("DocTypeYouAreWorkingOn", {

setup: function(frm) {

frm.set_query("FieldSelectedToApplyFilter", function() {

return {

filters: [

["TheDocTypeFieldLinksTo","FieldYouWantToFilter", "in", ["Value1", "Value2"]]

]

}

});

}

});

Here's one specific example for the Vehicle doctype if you are trying to filter the supplier to only those that supply vehicles or transportation services:

frappe.ui.form.on("Vehicle", {

setup: function(frm) {

frm.set_query("hauler_company", function() {

return {

filters: [

["Supplier","supplier_group", "in", ["Hauler"]]

]

}

});

}

});