I already read the info on the AWAB help here:
Open multiple widgets simultaneously—Web AppBuilder for ArcGIS (Developer Edition) | ArcGIS for Developers
but I think it is not matching what I need.
I have several in-panel widgets, I want these Panels to be floating panels over the map and to be possible to have few of them open at the same time (2, 3 or 4).
The Panels are closed automatically by the PanelManager with the method "closeOtherPanelsInTheSameGroup()" called in line 148 of file jimu.js/PanelManager.js.
First idea was to comment this line, and problem is solved, but I would like to override this behaviour by default, and then I don´t have to do it every time a new WAB version comes.