Renderings which are injected from partial designs are not editable on the page - it is like this by design. You can only edit content which is exposed by those renderings.
But! You can use page relative data sources for renderings on a partial. When you will drop a rendering on a partial, let say a Map rendering. You will probably:
- use local data source - map data source item will be created under the partial itself and you will see
local: syntax in the data source field of the Map rendering
- use global data source - you will point to the map data source item which will be located under the Data item in your site.
In both cases, the rendering won't be editable. Now! Let's assume that you are using local data source (
local: in the data source field). Simply replace the
page: and copy the whole Data from under the partial, under the particular page.
By doing this, you will be using pare relative data sources. While editing the partial you will be editing the local data source, but when you open a page which is using this partial, it will pick up data source item for the Map which is located under the page.