The From part of the query only has one attribute/property and that is the ID of the feature to retrieve related feature values from, such as shown by the example below from the feature Products.
XML:
<From id ='Product'/>
JSON:
"From": { "id": "Product" }
From only works on features that are defined as selectable, since this is the only way a feature gets its own identity and can have related feature values.
The from ID does, however, works on multiple features at the same time as shown by the following example:
This is very powerful in that it allows to distribute e.g. products across several features in case this was needed. Or perhaps search for Persons that for some reason need to be split across several Person archives etc.
Important
It is not recommended to use multiple features in the From, when using super wildcard ** (two star characters) to retrieve values for several configured features. Retrieval of Remote features may not make sense for all the features included in the From and may cause slow performance or simply fail. In such case, design and application of remote queries must be designed appropriately.
Supplier data queries
The From part of the query can be extended with a repository attribute/property if you want to retreive values from supplier items: