How do you setup a Structure to enable purchasable upgrades for unit hero on players team?
Please provide the correct steps for this newest version of map editor.
Take example on the Xel'Naga tower.
The ability type responsible to share the unit is "Interact".
You should not have difficulties to make it.
However, you must create Upgrades with help of Prerequisites (default way to create them).
Look for the Engeering Bay, it's one way (and laborious but more controllable) to organize upgrade levels.
More information here :
Have a nice day.