Yes, with a script column like this (and even easier with Opus v13):
function OnInit(initData) {
initData.name = 'ModifiedSpecial';
initData.version = '2023-10-21';
initData.copyright = '';
initData.url = 'https://resource.dopus.com/t/customize-grouping-function-group-by-modified-year-month-or-year-week-number/46544';
initData.desc = '';
initData.default_enable = true;
initData.min_version = '12.0';
}
function OnAddColumns(addColData) {
var col = addColData.AddColumn();
col.name = 'ModifiedSpecial';
col.method = 'OnColumn';
}
function OnColumn(scriptColData) {
// scriptColData.value = scriptColData.item.modify.Format('D#yyyy-MM');
scriptColData.value = scriptColData.item.modify.Format('D#yyyy-WW'); // week
}
Save ColumnModifiedSpecial.js.txt toββββ
%appdata%\GPSoftware\Directory Opus\Script AddIns
Toggle the column with
Set COLUMNSTOGGLE="scp:ModifiedSpecial/ModifiedSpecial(!,a,0)"