Backlink todo from quick edit

I ve created a coustom doctype, there I have a multiselect field, this is connected to todo. I can create a new todo with quick edit and it is safed in the custom doctype as expected.

I can open the todo from the custom doctype. But I can not find the way back from todo to custom doctype.
How can I set reference_name and reference_type automaticly during quick edit.