select a book. On title page select authors you are interested in and deselect others. Open book with parallel texts. Diglossa shows only translation you have selected.
Translation on a right page could be changed as a whole - select an author in a right header. But you can change translation of each paragraph with Shift-mouse-wheel over that paragraph.
On a left page you can select a wordform and fire search with Tab, or morphological analyser and dictionary - with Shift. (Only for sanskrit just for now).
Mouse pointer over a wordform with pressed Shift shows transliteration SLP1 for sanskrit.
Select other parts of a book in left header.
Esc key closes the popup window.