The ShackTac Fireteam HUD has been ported over to Arma 3, whee! This mod requires the CBA modset, which can be read about here (it is automatically installed when loading STHUD via PwS).
Watch the video for an example of how this mod functions.
You can read about the STHUD’s Arma2 version, which is functionally the same, here.
STHUD is part of the STUI compilation – download information can be found here.
If you run into issues with it, please post them to our tracker, here.