I open a modal dialog on click of a link. The modal dialog shows up a section which has a button named as "Attach" . On click of the button a local action is called to attach files. It comes in the form of an overlay( configured to open in overlay because I cannot open a modal dialog from an existing modal dialog). But using overlay the attachments which I add is not shown up on the section and also in the clipboard. I would like to know how to attach files from a modal dialog ?
Considering the scenario you posted, it's not possible to render more than one modal dialog/overlay on the screen. Request you to change the design to meet your business requirement (configure the attach files link control on the main screen, instead on overlay).