Zotero Script for moving custom field notes (e.g. imported from Citavi) to some field

moveCostumFieldNotesToField.js

// Move value from #CostumField notes with fixed label
// to a different field. Set these two fields according to your needs.

var label = "Signatur";
var field = "callNumber";
// List of all possible fields:
// https://api.zotero.org/itemFields?pprint=1
var check = true;
var overwrite = false;

var items = Zotero.getActiveZoteroPane().getSelectedItems();

function html2text(html) {
    var tempDivElement = document.createElement("div");
    tempDivElement.innerHTML = html;
    return tempDivElement.textContent || tempDivElement.innerText || "";
}

for (let item of items) {
    noteIDs = item.getNotes();
    for (let nid of noteIDs) {
        let note = Zotero.Items.get(nid);
        let skip = true;
        for (let tag of note.getTags()) {
            if (tag.tag == "#CostumField") {
                skip = false;
                break;
            }
        }
        if (skip && check) {
            continue;
        }
        var noteHTML = note.getNote();
        var noteText = html2text(noteHTML);
        Zotero.log(noteText);
        var parts = noteText.split(":");
        if (parts.length >= 2 && parts[0] == label) {
            parts.shift();
            value = parts.join(":");
            var content = item.getField(field);
            if (!content || overwrite) {
                item.setField(field, value);
	            item.save();
            }
        }
    }
}

items;

Here is a preview of its use: