[GNC] import map editor

Hallo all, can anyone explain the purpose of the "import map editor" shown in the tools menu? All what I can find related to mapping imports is this: https://wiki.gnucash.org/wiki/Bayes http://gnucash.1415818.n4.nabble.com/Fixing-confused-bayesian -matching-data-td4685819.html but there is nothing

shared expenses/IOU accounting

I may crack a nut with a sledgehammer but me and my girlfriend have different accounts for different purposes and currencies. Since our main bank doesn't allow us to use a sub account mutuality by issuing a second ATM card we use multiple cards/accounts depending on country and purposes. I would