XmCreateFileSelectionBox(3) on Linux
The text b95104ca8f68, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
The FileSelectionBox widget creation function "XmCreateFileSelection\%Box" "creation functions" "XmCreateFileSelection\%Box"