In game profile is option : native two axis joystick emulation. Enable it.
Explanation – Magic Dosbox emulates complete PC. Game profile tells what for hardware is inside. In other words, enabling option above tells that you inserted old dos cable joystick into emulated pc and this joystick supports axis.
In mapper you define conversion of your modern xbox gamepad events to something what these old games understand. For example convert xbox axis to keyboard keys, mouse or old axis from dos era. You should see options left joystick/right joystick, like is on the picture in earlier post.
But this is not enough. Now you must take manual of your dos game and read how our daddies implemented joystick support. Usually you can skip this paper and you can start SETUP.EXE, INSTALL.EXE or similar program included in game’s directory. If the game supports joystick then it should be there. Dont be surprised if the game does not support axis. Only few old games support axis. Mostly there is support only for state 0,1. Dos games were stupid and plug and play did not exist. You must run setup and tell what you need.
Which game do you try?