I am looking for short word that I can use instead of “not overridden”.
For example: “All promotions that are not overridden at the store level are included in the forecast.”
I don't think there's a good single word for what you describe, and your best bet is to turn the sentence around:
The forecast includes all items unless overridden at the store level.
The forecast includes all items except those overridden at the store level.
or even
Items overridden at the store level are not included in the forecast.
In politics, they say uphold ("The Congress upheld the President's veto.") You could use obey, follow, comply with, or observe, but there's a lot to be said for not override.
If there is a proposal that is not overridden, then that proposal is accepted or endorsed.
In technical senses the standard term is default. You customize the behavior of an application or a device by overriding the defaults.
I'm not aware of a single word for what you want, but I can re-write the sentence you give as:
All promotions that take priority at the store level are included in the forecast.
To say that the promotion "takes priority at the store level" means that it is not overridden by any other promotion from other levels.
For a single word in a drop-down list, you could use "prioritized".