Add Achievement to Challenge (RetroAchievement)
How to reach it
In Games & Emulation Main Screen visit the Achievements tab with the RetroAchievements table. Open the context menu (right click) and choose the Add to Challenge menu item.
How it works
This dialog lets you add a previously selected RetroAchievement to a Challenge.
Select a challenge with the Challenge dropdown. You can also add a challenge with the button.
Select a tier with the Tier dropdown. Add a tier with the button.
Decide if the achievement has to be unlocked in Hardcore mode with the Hardcore checkbox.
For reference, you can view any previously added achievements for the selected challenge / tier in the lower table.