Bash command line completion is functionality through which bash helps users by presenting possible options when the user presses the tab key enabling them to enter commands more efficiently,
To enable it source the provided script in one of your bash startup scripts (.bashrc for example):
source <Helix Install Dir>/scripts/qacli-completion.bash
and now your QACLI experience will be more user-friendly.
Press tab and it should auto-complete for most fixed items and provide files and directories for relevant commands. It will even capable of more complex completion, for example for CMA projects.