Luca, are we talking about a reference or a reference set? Your other question about this was about reference sets hence this question.
Let say you have a main object with inside some dataview (that is my assumption of your current setup and problems). Inside the dataview you want to set some reference set. Inside the dataview you can create a custom save button which only does a commit on the dataview object.
If you have a reference instead of a reference set you could also use an on change microflow on the reference that commits the dataview object.
Hope this helps, otherwise elaborate on what kind of error you are getting. And a screenshot of the form might help.