Some website pages have multiple form elements with same name, for example login form in site header, and same form in content area. And there are no wayы to detect only one item via Bitwarden custom fields.
For solve this problem will be good to allow fill DOM elements selectors for locate only needed elements to auto-fill. Something like .main-content form.myform input.login
Not specifically the solution you’re asking for, but I’m wondering if any of the options listed on the help page might be applicable to you?
Via current “custom fields” I can use only separate element info, so if both passwords fields have same name and id (but various parent elements), I can’t point to one of them 
Currently the function of custom field can only be selected using the id, name, placeholder, aria-label of the input field.
The username or password fields of some web pages cannot be simply pointed to by id, name, placeholder, aria-label.
If I can select according to the syntax of querySelector (css selector), no matter how the input field of the web page is implemented, there will be a way to make the corresponding selection.