You can add a Panel with Transparent Background that cover whole activity and:
1. Add one of the great wrappers of progress circle in this forum (
@DonManfred https://www.b4x.com/android/forum/threads/donmanfreds-overview.54618/, etc..)
2. Add a GIF image onto it (I know, maybe not best solution)
3. Maybe a imageview with circle image rotating (
@Informatix NineOldAndroid, Animations Plus,etc...)
When operations finish, hide the panel.
P.D:
Don't know if solution 1 runs on another thread than UI thread